Review the passage:
Ralph spent all his savings on a diamond ring to give
to his girlfriend Gloria. A greedy young woman who had a box full
of expensive trinkets from ex-boyfriends. Gloria was always looking for
a man with a fat wallet.
You chose the first part, Ralph spent all his savings on a diamond ring to give to his girlfriend Gloria. This part has a main clause: Ralph is the subject; spent is the verb. A fragment will not have a main clause.