Allowing Face-To-Face Communication During a Commons Dilemma Game Can Work

Allowing face-to-face communication during a commons dilemma game can work to increase cooperation.Why does the text suggest that communication works?

A) It helps the individual to persuade everyone else to see things from his or her perspective.
B) Communication can help to establish a sense of group identity.
C) It helps to pass the time more pleasurably and people will like each other when they're having fun.
D) It helps to toughen group members up so that they can play more competitively
E) There tends to be less normative pressure when people get to know each other.