某线性定常系统的单位斜坡响应为：<img src="https://static.zxtiku.com/wangke/imgs/topic/8df2e5d615284034a012fdd4d7f5642b.jpg"/>，则其单位脉冲响应为（）。 A. <img src="https://static.zxtiku.com/wangke/imgs/topic/0c285ffa0ba243155204b4ae52ca4467.jpg"/> B. <img src="https://static.zxtiku.com/wangke/imgs/topic/9a109ea4b24357a9ee95b399f992ae72.jpg"/> C. <img src="https://static.zxtiku.com/wangke/imgs/topic/6a35de97dd62b0b87eb57da77405d5bb.jpg"/> D. <img src="https://static.zxtiku.com/wangke/imgs/topic/8e054f0fa3090b5a83ceaeb9075b88f1.jpg"/>