Why Would a Race Track of All Places Be an Excellent

Why would a race track of all places be an excellent place to conduct research on post-decision dissonance?

A) The odds are against inexperienced bettors, but experienced bettors are more likely to win money than to lose it.
B) It's a place where the consequences of both permanent and impermanent decisions can be systematically studied.
C) Trainers, owners, and jockeys have invested a lot of time and effort to breed and train a winner.
D) A lot of people go to watch the races, but not everyone believes that betting is moral.
E) It is a large random sample of people.