(1) Courtney is one of the many teens who help others. (2) Last year, 60 percent of the nation’s teens volunteered 2.3 billion hours to a social or political cause. (3) Of those hours, 1.8 billion were given to national organizations. (4) These numbers show that teenagers care about others.

Which sentence in this paragraph from “Youths Offer a Helping Hand” by Tameeka Mithem is the topic sentence?

A.sentence 4

B.sentence 1

C.sentence 2

D.sentence 3