如图所示，一木桩的顶角为,，桩和泥土间的摩擦角为，则桩打入后不滑出的条件是？<img src="https://static.zxtiku.com/wangke/imgs/topic/365653b204d61886ce4259db35f077fb.jpg"/><img src="https://static.zxtiku.com/wangke/imgs/topic/a0b4e54435bec80c34b6de1a13983459.jpg"/> A. 选项A B. 选项B C. 选项C D. 选项D