Mark the letter A, B, C, or D to indicate the sentence that is best written from the words/ phrases given.Câu hỏi What /you/use to do/your free time/a child? A. What did you use to do in your free time as a child? B. What did you use doing in your free time as a child? C. What do you used to do in your free time when a child? D. What were you used to do in your free time as a child?