He has difficulty ___ the worda、to pronounce b、 for pronouncing c、 pronouncing d、 of pronouncing

He has difficulty ___ the word
a、to pronounce
b、 for pronouncing
c、 pronouncing
d、 of pronouncing

c、 pronouncing ;
have difficulty (in)doing sth:做某事有困难；
前面省略了介词in；

A

C., pronouncing

c
少了个介词