询问职业：What do you do? — 英语选择题
题目
Tom 正在参加学校举办的「职业体验日」活动。他先遇到了王阿姨，王阿姨说："I work in a hospital and I help sick people. I am a nurse." 接着李叔叔告诉他："I drive a bus every day." 最后一位张先生正在给病人看病，他说："I am a doctor." 晚上妈妈问 Tom："What does 李叔叔 do?" 根据对话，Tom 应该回答：______
A. He is a doctor. B. He is a nurse. C. He is a driver. D. He is a worker.