A Non-disclosure agreement (NDA) is designed to protect sensitive information, ensuring that proprietary details disclosed during business negotiations or collaborations are not shared with external parties. It is the best choice in scenarios where sensitive information is involved but does not impede a company's operations outside of protecting the specific information outlined within the agreement. This is why it is common in contractor and client relationships during network projects. Other options such as SLA, MOU, and BYOD policy do not appropriately address the need for confidentiality of proprietary information in this context. A Service-level agreement (SLA) focuses on service performance rather than confidentiality, a Memorandum of understanding (MOU) is an agreement between two or more parties indicating an intended common line of action but not necessarily confidentiality, and a Bring your own device (BYOD) policy governs the use of personal devices in a corporate setting.