If something happens to the brain's development during pregnancy, it is more likely ______ affected in a male.

【正确答案】 C

【答案解析】解析：be likely to do sth．表示“可能……”，由于不定式的逻辑主语为不定式所表示动作的承受者，故用不定式的被动形式，选项C正确。