Jonah studied for 3 hours longer than Sierra. he also studied for 3 times as many hours as William. these relationships are shown on the graphs below. which statement is true if Jonah studied for 6 hours?
 A) William studied for 3 hours longer than Sierra
 B) Sierra studied 3 hours longer than William
 C) William studied for 1 hour longer than Sierra
 D) Sierra studied 1 hour longer than William