SAT （the delegates coming this far）,they did not want to ret

SAT
（the delegates coming this far）,they did not want to return without accomplishing something.
A,The delegates coming this far,they
B,Coming this far,the deleates felt they
C,Having come this far,the delegates
D,To come this far ,the delegates
E,The delegates came this far,so that they
我选的是D,可是答案是C.为什么不能选D呢?
还有我想问一下v+ing,.或.,V+ing...是不是表示因果关系的?