SC: In 1990, a charitable foundation presented the local

[direstraits007]

In 1990, a charitable foundation presented the local branch of a national chain of grocery stores with a humanitarian award for wheelchair access ramps that it had installed well before local law required.

a. wheelchair access ramps that it had installed well before local law required

b. wheelchair access ramps that had been installed well before local law required it

c. the installation of wheelchair access ramps well before local law required

d. having installed wheelchair access ramps well before local law required them

e. having installed wheelchair access ramps well before local law required

Source: Princeton Review.

IMO C.
please explain your answer.

Thanks!

GeeMate.

[cyber_office]

What is the answer according to Princeton Review? Is it E or C?

Thanks.