If you receive a written invitation to an event that says RSVP, what should you do?

A.respond to the invitation one day before the event.

B.write a “thank you” letter to show your gratefulness for the invitation

C.let the person who sent the invitation know whether or not you plan to attend

D.give no response to the person who sent the invitation

正确答案： let the person who sent the invitation know whether or not you plan to attend