In the Above Decision Tree,Matthew Picks First and Dean Picks

Multiple Choice

In the above decision tree,Matthew picks first and Dean picks second.Matthew and Dean both know the payoffs to each choice for both themselves and each other.
-Refer to the decision tree above.The equilibrium of the game results in relatively low payoffs for Dean and Matthew.This is because of a(n)

A) prisoner's dilemma.
B) lack of equilibrium.
C) commitment problem.
D) credible threat.
E) incredible threat.