When a computing environment requires that some processing of applications takes place on a server and on a PC-class computer, which type of system are you using?

The correct answer to the following question will be "Client/server system".

Explanation:

A computational device consisting of two pieces of logic, such as:

A client (requests to a server for their service). A server (they provide services to the client).

A type of software design composed of dual components such as server and client systems, all operating over the network of computers is on the same device, is known as the Client-server system.

A client requests the server to provide the services, and the server delivers the service to the client as per their wishes if they are available.

So, it's the right answer.