无重直杆AC的A端靠在光滑的铅垂墙上,B处为光滑接触点,C端挂一重为P的重物,且直杆处于平衡状态。以下四图中哪一个是其正确的受力图,( )。

A、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/153967360275337ff9264a6af4ca991864dee40301ddb.png" alt="上传图片">

B、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1539673622304500903e4d2d24d3b94f8f7e87ebef53b.png" alt="上传图片">

C、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1539673639385a46455b4def6491b9c1dc213ac22537f.png" alt="上传图片">

D、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/15396736654459f369b1e52244ed9a723c1dd87e97270.png" alt="上传图片">