The gametophyte is much larger than the sporophyte in all of the following except
a. mosses.
b. liverworts.
c. pine trees.
d. horsetails.

The answer is C. Pine trees

To answer this question we just have to find out the organism which sporophyte the dominant life stage

Pine Trees sporophyte is the dominant one in their live..  On the pinetrees, the gametophyte is much smaller than the sporophyte

That would be a working theory.