设抛物线C：y²=2px（p＞0）焦点为F，其准线与x轴的交点为Q，过点F作直线交抛物线C于A、B两点，若∠QBF=90°，则|AF|-|BF|=______．

“Don't get near to it.It’s too dangerous!” “_____”

A．Yes, I won't

B．No, I don't

C．No, I can't

D．No, I won't