While reviewing a penetration testing script written in Python, you identify a function designed to process a list of hostnames and their associated services. The goal is to add a tuple containing a new hostname and service to the existing list, while ensuring that this addition is the last element and maintains the list's structure. Which of the following methods should you choose to accomplish this while adhering to best practices and considering performance?
Expanding the list with extend() method using the host and service tuple
Using the += operator to concatenate a new list with the host and service tuple
Using the append() method for the host and service tuple
Utilizing the insert() method, providing the index as the current list length for the host and service tuple