請教各位關於此題
The increase in profits during the third quarter was ___
due to a national advertising campaign.
A.almost
B.most
C.mostly
正確答案為C,但為何不是B 或A呢?
謝謝~!

我覺得是考詞意沒錯欸 畢竟due是形容詞而三個選項都是副詞這樣