Given the task definition and input, reply with output. In this task, you will be shown a conversation. You need to write a question with three choices for the conversation. Your question should be answerable based on the conversation and only have one correct answer. Note that you don't need to answer your question. "W" and "M" in the conversations stand for "woman" and "man".

M: There are millions of web pages on the net. How do I find what I'm looking for? W: Use a search engine like Baidu and Google. M: How does it work? W: You enter the name or topic you are interested in and ask the search engine to find pages about your topic. M: How do I use a search engine? W: Let me tell you step by step. M: OK! W: At first, we can go to the website address and then type the keywords. M: Then it will search automatically? W: Yes, it will show a lot of websites with the keywords. M: If I find the website I need, what should I do? W: That's easy, click the website, and you can enter. M: Thank you for your help!
What's the conversation mainly about? (A) How to use a search engine. (B) How to build a website. (C) How to communicate with others on the net.