I don't know whether he is( ) to .he somtimes makes things worseA.possible B.able C.afraid D.easy

I don't know whether he is( ) to .he somtimes makes things worse
A.possible B.able C.afraid D.easy

填:B.able
be able to 能够
I don't know whether he is (able ) to.后省略了动词原形及宾语:do it /help
句意:我不知道他是否能帮上忙.他有时把事情弄得更糟.