What Effect Does Exposure to Media Violence Have on Aggression

What effect does exposure to media violence have on aggression?

A) Exposure to violent films increases aggressive behaviour in the lab,but decreases aggressive behaviour in the field.
B) Exposure to violent films increases aggressiveness,but violent music videos and song lyrics do not increase aggressiveness.
C) Most forms of media violence actually reduce aggression by providing a socially acceptable release of pent-up aggression.
D) All forms of media violence appear to increase aggressive behaviour.