Why do you set out so early in the morning?

问题描述:

Why do you set out so early in the morning?
······Why do you set out so early in the morning?
······——the rush hour.
A.Avoiding B.avoided C.To avoid D.Avoid
为什么选C不选A

不定式,有表示目的的意思.动名词,或者现在分词都没有这个作用.
把全句都说出来,就是:
Why do you set out so early in the morNing?
I do so to avoid the rush hour.