-Will he ____ come next month -I don't know so A be able B can C be able to D is able to

-Will he ____ come next month -I don't know so A be able B can C be able to D is able to
-Will he ____ come next month -I don't know so A be able B can C be able to D is able to

-Will he ____ come next month -I don't know so A be able B can C be able to D is able to
c will是情态动词,后面跟动词原形,当然,不能在情态动词后再加情态动词,所以排除B和D,同时 be able to do是固定用法,去除A,所以选c