Recent Studies Examining Police Behavior in "Shoot or Don't Shoot

Recent studies examining police behavior in "shoot or don't shoot" simulations have found that

A) police and civilian participants show no differences in performance.
B) racial bias in performance on the task tends to increase over time, unlike college student participants, who show the opposite pattern of results.
C) even when they are able to avoid racial bias in their decisions, they sometimes take longer to make decisions that go against racial stereotypes.
D) None of these