By Exposing Their Followers to the Arguments of the Opposition

By exposing their followers to the arguments of the opposition, then refuting them, one-by-one, theologians and politicians ______.

A) unintentionally encourage their followers to believe the opposition
B) have little effect on their followers' beliefs, either way
C) give their followers a sort of psychological immunity to the arguments of the opposition
D) often discourage their followers, causing them to disregard both sides of the argument