图示单自由度动力体系自振周期的关系为（          ）

<img src、"http://sichuan.ouchn.cn/pluginfile.php/61596/question/answer/255260/7/247748/image034.png" alt="" width="49" height="17">

<img src、"http://sichuan.ouchn.cn/pluginfile.php/61596/question/answer/255260/7/247749/image035.png" alt="" width="49" height="17">

<img src、"http://sichuan.ouchn.cn/pluginfile.php/61596/question/answer/255260/7/247750/image036.png" alt="" width="49" height="17">

、都不等