Mark the letter A, B,...

Câu hỏi: Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions
Those who are riding a motorbike are not allowed to take off their helmet.

A. People must never take their helmet off while they are riding a motorbike.

B. Those who are wearing a helmet are not allowed to ride a motorbike.

C. It is the helmet that one needn't wear when he is riding a motorbike.

D. You should not wear a helmet when you are riding a motorbike.