You must never take your helmet off while you are...

Câu hỏi: You must never take your helmet off while you are riding a motorcycle.

A. When you are riding a motorcycle, wearing a helmet is not a must.

B. You needn't wear a helmet whenever you are riding a motorcycle.

C. Helmets must be worn at all times when you are riding a motorcycle.

D. If you are riding a motorcycle, you needn't wear a helmet.