I'm afraid _____ home at night.A.to walk B.of walk C.walk D.walking

I'm afraid _____ home at night.
A.to walk B.of walk C.walk D.walking

A,be afraid to do sth.A是答案.
B的搭配应该是be afraid of sth,后边跟名词,或者是动名词,就是动词的ing形式.
C和D都不对.