The correct answer is: C. Client
A client is a computer or software that requests a service from another computer or software, known as a server. In the context of the question, the client is the computer that is requesting web pages from the server.
A server is a computer that provides a service to other computers or software. In the context of the question, the server is the computer that is hosting the web pages that the client is requesting.
A host is a computer that is connected to a network and can be accessed by other computers on the network. In the context of the question, the host could be either the client or the server.
A router is a device that connects two or more networks together. In the context of the question, the router is not directly involved in the request for web pages.
Here is a diagram that illustrates the relationship between a client, a server, and a router:
The client is connected to the router, which is connected to the server. The client sends a request for a web page to the server, and the server sends the web page to the client.