“A computer________ think for itself. It must be told what to do

“A computer________ think for itself. It must be told what to do.”
A、can’t
B、couldn’t
C、may not
D、might not
【正确答案】：A
【题目解析】：考查情态动词。could、may和might表示的都是一种可能性，只有can表示的是能力，而本题指的电脑是不能自己思考的，因此选can't。