Which feature can help prevent excess unauthenticated requests to the server?

Implementing security measures such as CSRF (Cross-Site Request Forgery) protection is essential for preventing excess unauthenticated requests to the server. CSRF protection works by ensuring that requests made to the server come from authenticated and authorized users. It does this by using tokens that are verified before processing each request. If a request does not contain a valid token or is made from an unexpected source, it is rejected, thereby safeguarding the server from unauthorized and potentially harmful interactions.

This protective mechanism helps to ensure that only legitimate users can execute actions that affect the server, minimizing the risk of excessive and potentially malicious requests that could harm server performance or security. Other strategies like load balancing, server optimization, and retry mechanisms can enhance performance and manage traffic, but they do not specifically address the concern of preventing unauthorized requests. Thus, the focus of the correct answer is on maintaining security and integrity within the application by controlling who can make requests to the server.