Caller: "Hello, is Mr. Smith there, please?" Receiver: "I'm sorry, he's not available at the moment. Would you like to leave a message?" Caller: "Yes, please tell him John called about the meeting tomorrow. It's at 10 AM, not 9 AM." Receiver: "Got it. I'll pass on the message." What is the main reason John called Mr. Smith?
A) To cancel the meeting.