Which of the following is a benefit of a Content Delivery Network (CDN) that involves adding servers to help process the same workload?

The benefit of a Content Delivery Network (CDN) that involves adding servers to help process the same workload aligns with the concept of horizontal scalability. Horizontal scalability refers to the practice of adding more machines or servers to a system to handle increased load, rather than upgrading the existing hardware (which would be vertical scalability).

In the context of a CDN, when traffic increases, more servers are added across various geographical locations to distribute the workload, thereby enhancing performance and ensuring stable service for users. This approach helps in managing large amounts of simultaneous requests while maintaining quicker load times and improving overall user experience. The distributed nature of CDNs is particularly effective as it reduces latency and allows for better resource utilization.

The other options do not apply in this context. Vertical scalability would refer to upgrading the existing servers, which does not directly relate to how a CDN operates. Improved website security is a benefit of CDN services, but it does not specifically relate to the mechanics of scaling. Vertical redundancy generally refers to having backup or alternative systems in place to increase reliability, which is not directly related to the concept being discussed here.