Answer:
B. There was a dramatic increase in church membership.
Step-by-step explanation:
The Second Great Awakening was a period of religious revival, meaning that lots of people (Americans, because U.S. history) started to care about religion again. so A. and C. isn't right
During this historical event, people have been converted to all kinds of religions, not just Catholicism (also Christianity, etc.). so D. isn't right
With this said, the best answer that actually makes sense (and is also the remaining answer) would be B.