已知 <img src="https://static.zxtiku.com/wangke/imgs/topic/1de83c9f25d59d9543a9578883f9c908.jpg"/>则信号<img src="https://static.zxtiku.com/wangke/imgs/topic/ee2c3eb3d25e16e741bbefd35ba320d2.jpg"/>的傅里叶变换为 A. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/53834a895e620db3b489293ec4c520bb.jpg"/> B. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/2f55ac223bec70704cd2705ef1fad5ec.jpg"/> C. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/7c9c8af90c8ccbf3fae624a39ea6cd3a.jpg"/> D. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/5c04e8c461ea4bf0f00b6c59ca25107f.jpg"/>