The Prisoner's Dilemma Game Is an Excellent Vehicle for Studying

The Prisoner's Dilemma game is an excellent vehicle for studying social conflicts in the laboratory because

A) researchers can systematically vary the strategies participants use.
B) there are clear winners and clear losers, and thus reliable dependent variable measures.
C) there is one and only one right answer to the problem.
D) people's actions in the game seem to mirror many conflicts in real life.
E) the variables of the game are clearly defined.