How should a web application be designed to work on a platform where up to 1000 requests per second can be served?

How should a web application be designed to work on a platform where up to 1000 requests per second can be served?
A . Use algorithms like random early detection to deny excessive requests.
B . Set a per-user limit (for example, 5 requests/minute/user) and deny the requests from the users who have reached the limit.
C . Only 1000 user connections are allowed; further connections are denied so that all connected users can be served.
D . All requests are saved and processed one by one so that all users can be served eventually.

Answer: D