Plz hurry it's !
which clause is subordinate?
a. before long, we arrived at the library.
b. after i returned the overdue library books.
c. everyone piled into the car.
d. there was a fine to pay the librarian.

D is the answer because there was a fine to pay the librarian

The sentence needs a descriptor of exactly "what" will happen at gurley and marina. in this case, it is the light at the intersection turning green. in this case, the sentence could be rewritten as "the light at the intersection of gurley and montezuma will turn green exactly three seconds after the light at the intersection of gurley and marina."