the more difficult、 the most difficult、 a most difficult、 a more difficult的区别

问题描述:

the more difficult、 the most difficult、 a most difficult、 a more difficult的区别
It is____question but not the most diffcult one in the examination paper.
A.the more difficult B.the most difficult
C.a most difficult D.a more difficult

答案应该是C吧
more应该只用于比较 是出现对比的时候才用
the most是* the most difficult就是 最难的
a most 相当于very 就是非常的意思