It was a matter of ---would take the position.A.whoever B.wh

of 是介词,后面是宾语从句.
从句缺少主语.
不用C.因为whomever的意思是无论谁.而这里不是无论谁的意思.这里应该选的是D.who would take the position.
由who引导的一个问句!whomever是不引导问句的!