题目1单选题
某因果LTI系统的系统函数<img src="https://tihai-oss-cloud.itihey.com/img/771e83ca7f2980e0c907662c5992e066.png">,则其收敛域为 ( )A. <img src="https://tihai-oss-cloud.itihey.com/img/15e73801a2e6ec915ad44240fd7fa3b1.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/a4ba1c280eca401ab5694063ae6ca03b.png"><img src="https://tihai-oss-cloud.itihey.com/img/30cc3792f58f1e4f7e4e2ab5a08df5ee.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/2bfac482363adf81ccb2cde4489976f9.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/0785fd302134dfc2958341cc64361bbf.png">