Methods are actions that can be performed on objects. A method that calculates the total cost, including taxes, would likely take parameters or use internal variables and then return the calculated value. 'invoice.calculateTotal()' is the correct way to call a method named 'calculateTotal' for an object 'invoice'. The method name follows the object name separated by a dot, which indicates that 'calculateTotal' is a method belonging to the 'Invoice' object.

Maintaining and reviewing logs is the correct answer because logs track user activity, changes made to files, and system events. This information can be used to pinpoint when the unauthorized changes were made and by which user account, facilitating a proper investigation of the incident. It is an essential part of IT security to ensure accountability. Regular audits would involve reviewing such logs but they are not as direct in addressing the specific incident. Password changes, while important for security, would not directly reveal who made the file changes. Firewalls and backup restorations do not provide information about specific user activities.

Sharing files over the Internet can expose sensitive information to unauthorized individuals if the file sharing method is not secure. Utilizing untrusted or unsecured services could lead to confidential data being accessed by unintended parties, which may lead to identity theft, financial loss, or data breaches. It is crucial to use secure, authenticated methods for file sharing to preserve confidentiality and prevent unauthorized access.

The correct answer is Primary key constraint. A primary key constraint uniquely identifies each row in a database table and cannot be null. It is used to enforce the uniqueness of the row data and serve as an identifier for referencing the rows. A Unique constraint ensures that all values in a column are different but does not prevent null entries. Foreign key constraint is utilized to maintain the referential integrity between two tables, not for uniqueness within one table. The Check constraint is used to specify a predicate that all tuples must satisfy, but it does not enforce uniqueness nor prevent nulls by itself.

A 'Single use' license means that the software can be installed and used on one computer only. This is crucial for compliance as installing it on multiple computers with just one license would violate the terms.

GB stands for Gigabyte, a unit of measurement used to quantify digital information and represents approximately 1 billion bytes. It's important to differentiate between Gigabytes and other units of measure because they represent vastly different quantities of data. For example, a Megabyte (MB) is equal to approximately 1 million bytes, and a Terabyte (TB) represents approximately 1 trillion bytes. Understanding these differences is essential when working with digital storage.

A 'for' loop is used when you know in advance how many times you want to execute a statement or a block of statements. In the context of the task required by the IT technician, a 'for' loop allows the program to perform the task exactly 10 times. The other options do not specify the number of repetitions or relate to entirely different programming concepts.

A schema in a relational database is an outline or blueprint that defines how data is organized, including the structure of tables, columns, and relationships. You can think of it like an architectural plan for a building, describing the rooms (tables), their characteristics such as size and shape (fields/columns), and how different parts of the building connect (constraints and keys).

When a disaster occurs, an organization may not have the resources or time to restore all systems at once. Prioritization ensures that the most critical services, which the business heavily relies on, are restored first to maintain key operations. This concept helps to minimize the downtime and operational impact during the recovery process.

HDMI and DisplayPort are both used for high-resolution displays, but DisplayPort typically supports higher resolutions and refresh rates than HDMI. Therefore, DisplayPort is the better choice for the best video quality on high-resolution monitors. VGA and DVI are older standards that do not support as high resolutions as HDMI or DisplayPort. Mini DisplayPort is similar to DisplayPort, but it is not as widely compatible as the full-sized DisplayPort connector.

A forward proxy with content filtering capabilities would allow the administrator to enforce a content filtering policy, blocking access to specific sites as per the institution's guidelines. Concurrently, it would cache frequently accessed content, speeding up subsequent access for users. A reverse proxy, while commonly used for load balancing and SSL offloading, does not typically provide content filtering. An SSL/TLS proxy can decrypt and inspect SSL/TLS traffic but does not inherently provide content caching. A VPN service primarily provides remote access and encryption, which are not aligned with the stated requirements.

This statement is incorrect. Main memory, also known as Random Access Memory (RAM), is used temporarily to store information that the CPU needs while a computer is on; it does not store data permanently. When the power is turned off, data in the RAM is lost. Permanent storage is typically achieved with storage devices like hard drives, solid-state drives, or cloud storage where data persists even when the computer is turned off. Understanding the difference between temporary and permanent storage is crucial for IT professionals.

A constant should be used to represent the number of weeks in a year because this value is fixed and should not be altered during the program's execution. Declaring a constant instead of a variable ensures the safety and consistency of the data. Using variables for fixed values can lead to accidental changes and bugs.

Marcus should use a scripting language because it allows for quick and easy edits, can be run immediately without compiling, and is generally cross-platform compatible, which meets the requirements for the automated tool he is tasked with creating. Scripting languages are commonly used for automating repetitive tasks and manipulating data, which aligns with the process of generating and sending weekly reports.

The statement is correct. Variables are indeed named locations in memory where data is stored. During program execution, the value of a variable can be read or changed, which makes them essential tools for programming to handle data manipulation and processing.