英语选择题 Send it to ------- is in charge of sales

英语选择题 Send it to _______ is in charge of sales
英语选择题 Send it to _______ is in charge of sales
A whoever B whomever C who D no matter who
答案选了A
这里的空到底是要看to后+宾语 还是这个空是is前的主语呢?
为什么不能选BD