3 A: Is 3:45 OK for you? B: a Not really, my tennis lesson finishes at 4:00. b See you there.

If 3:45 is not convenient, the response should indicate a conflict or a need for adjustment. Option a, "Not really, my tennis lesson finishes at 4:00," explains why 3:45 is not suitable and implies a need to reschedule or adjust.

Answer: a