THEY WANTED TO KNOW WHY THEY ... IT FOR HER WHILE SHE COULD DO IT...

166. - 2000 CAU TRAC NGHIEM ANH A B C
2000 CAU TRAC NGHIEM ANH A B C

166. They wanted to know why they ... it for her while she could do it

by herself.

a. did

b. have done

c. should do

d. have to do

--> c