Chọn đáp án đúng: Ann: "Thank you for a wonderful evening." - Karen: "_____________."

Mark the letter A, B, C, or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges.
Question 19. Ann has just had dinner at Keren’s.
- Ann: "Thank you for a wonderful evening." - Karen: "_____________."
A. You're welcome B. Thanks a lot C. Have a good day D. Cheers
Question 20. On discussing the problems with Peter in the office, Mary felt hot.
- Mary: “It is very hot in here. ____________?”
- Peter: “Of course.” A. Must you open the window
B. Shall you open the window C. Could you open the window D. A or C