Final Answer:
Based on the diagram, the type of proxy server handling the client's request is a Reverse proxy server.
Step-by-step explanation:
A reverse proxy server sits between client devices and a web server, acting as an intermediary on behalf of the server. In the context of the diagram, the client is making a request, and the proxy server is forwarding that request to the appropriate web server. The reverse proxy server is often used for load balancing, security, and caching purposes. It hides the details of the internal servers from external clients, enhancing security and optimizing resource utilization.