it is a matter of ________ would take the position?

问题描述:

it is a matter of ________ would take the position?
a,who b,whoever
选哪个为什么?
此题答案为B

(it is a matter of ________)缺少宾语成分
后半句(________would take the position?)缺少主语成分
需要一词既能充当宾语又能充当主语,那就是whoever =no matter who