【单选题】
如右下图所示,OC=60.500m,β(∠AOC<sub>0</sub>)-β<sub>1</sub>(∠AOC)=+30″,则CC<sub>0</sub>的值为()。<br /> <img src="https://nimg.ppkao.com/2019-05/wanxiaokui/2019050912301615130.jpg?sign=7ce0e3989ad73530a281a5f1fde2f9f9&t=62d5bf47" />
A、+0.009m
B、–0.009m
C、–0.0045m
D、+0.0045m