某系统的传递函数为,则该系统的单位脉冲响应函数为( )

A、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/15177952316295d5b3a0174694358a8529b99d361c43eimage33.png"/>

B、5t

C、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/151779523169505fcb9c33d3d41a891745f1e3b522119image34.png"/>

D、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/151779523179700a4c45a1e1e4eeb940488ef7e2cf854image35.png"/>