答案是D.fairly
I don't fairly like the idea of walking home in the rain.
我不是很喜欢在雨中走回家.
fairly是程度副词.
在做副词用时,
A so 、B very 表程度时,没有这种用法,一般用修辞形容词或者副词,例如：I don't like him so much；I don't like him very much.
C much,单独用时,一般不放在在实义动词之前,放在句末居多,例如：I don't like him much 我不太喜欢他.
觉得满意的话,如果不太明白,欢迎追问.