A. to move to a big city B. not to move to big city C. not to move to a big city without thinking about the problems there D. not to think too much about the problems before they move at a big city 参考答案:C 答案解析:根据本文最后一句,作者告诫人们在去大城市之前,认真思考一下那里的问题,故 C为正确答案。