听力原文：W: I read the instructions, but I'm still not sfire how to use my cell phone.
M: Actually, it's pretty easy. First of all, don't forget to turn it on.
W: Got it!
M: Then dial the number. And remember to press the "send" button.
W: That's all？
M: Pretty much. Just make sure to recharge the batteries every few weeks. And try not to drop it. It's fragile.
W: Good advice.
M: And one more thing: Be sure to pay the phone bill every month!
What is the conversation mainly about？

A. How to read the instructions.
B. How to use the cell phone.
C. How to pay the phone hill.