题目内容：

___________ the most important subject?-----English A Do you think which is B Which do you think is
书上答案是B,但我感觉不大对,

优质解答

答案肯定是B没错,这是英语疑问句的正确语序.
要注意的是,which才是主语,而do you think是插入语,也就是不影响句子构成,可以可无的成分,插入语都是放在句子中间的.