—I think students should have mobile phones to call their parents.—. They often use them t

问题补充：

—I think students should have mobile phones to call their parents.

—. They often use them to play games instead.

A. I hope so

B. I don agree

C. No problem

D. Good idea

答案：

A. I hope so

(答案→)B. I don agree

C. No problem

D. Good idea

解析：I hope so希望如此; I don agree我不同意;No problem没问题;Good idea好主意.句意:我认为学生们应该有手机,来给他们的父母打电话.联系下文,他们反而经常用它们来玩游戏.可知前文为否定回应,故选B.