Researchers Have Found That Exposure to Different Races, Ethnicities, Religions

Researchers have found that exposure to different races, ethnicities, religions, and social classes may in fact lead to exclusion.What idea does this highlight?

A) Exposure to different people or things may heighten the threat level that people feel.
B) Exposure to different people or things may heighten inclusive feelings.
C) Exposure to different people or things may heighten a group leader's power.
D) Exposure to different people or things may heighten coalition.