直角均质弯杆ABC，AB=BC=L，每段质量记作mAB，mBC，则弯杆对过A且垂直于图平面的轴A的转动惯量为（）。<br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/1f41aad9fdcac5ad136b5f7d290eb375.jpg"/><br/> A、<img src="https://static.zxtiku.com/wangke/imgs/topic/66d8a447f7a254458376693482fa430a.jpg"/><br/> B、<img src="https://static.zxtiku.com/wangke/imgs/topic/a855cf1593a6bd1ff79ba1bee7a70543.jpg"/><br/> C、<img src="https://static.zxtiku.com/wangke/imgs/topic/84a759fb23212b20f8f8b84b114b8637.jpg"/><br/> D、<img src="https://static.zxtiku.com/wangke/imgs/topic/2047e893657ba21567f8e5e456e17688.jpg"/>