Mark the letter A, B, C, or D on your answer sheet...

Câu hỏi: Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

Your sister has lost an awful lot of weight. She must have been on a diet,_________?

A. mustn't she

B. needn't she

C. haven't she

D. hasn't she