Which of the following sentences do not contains grammar error?()

Which of the following sentences do not contains grammar error？()

A、The number of people who own cars are increasing

B、When a student need to remember is that when taking an exam, you should not cheat

C、As a college student, we should use personal computers in a proper way

D、Mar likes hiking,swimming, and riding a bicycle

请帮忙给出正确答案和分析，谢谢！