2-4-5、序列<img src="https://static.ppkao.com/wangke/imgs/topic/f6320200b560c0fbc9701420e684e877.jpg"/>的Z变换为（）。 A. <br /> <img src="https://static.ppkao.com/wangke/imgs/topic/28d07e567f3a7b6838885079347c615c.jpg"/> B. <br /> <img src="https://static.ppkao.com/wangke/imgs/topic/370512ce12e0f01cdc3b7f41ce98c1fe.jpg"/> C. <br /> <img src="https://static.ppkao.com/wangke/imgs/topic/5306b2af37d1faf1a8e21cd257ed70ae.jpg"/> D. <br /> <img src="https://static.ppkao.com/wangke/imgs/topic/b10bee6dfafbaaf62647d6e9a9c8ff21.jpg"/>