听力原文：W: Good afternoon, Uncle Smith.
M: Good afternoon, Cathy.
W: There will be a dinner party for my birthday. Would you come？
M: I'd love to. When？
W: Next Saturday.
M: I'm afraid I'm busy then. I have to meet a foreign friend at the airport.
W: That's OK. What about Sunday？
M: That will be all right.
W: That's great. You can come at around 7:00 and we can chat for a while before the party starts.
Why did Cathy invite Uncle Smith to dinner？

A. Because she had some questions to ask him.
Because she had no other friends.
C. Because she wanted to have a birthday party.