Question

A paragraph is defined as a group of sentences that center on a

A. Controversial topic
B. Central idea
C. Number of supporting details
D.set of statistics

Answer 1

The answer is B, a central idea. 

Not every paragraph ever is about something controversial, nor are they always about statistics. Maybe supporting details could work but they aren't the centerpiece, just supports for the main theme.

Answer 2

B. Central idea would most likely be the answer