Evidence Suggests That ___________ Require _______________ in Order to Coordinate

Evidence suggests that ___________ require _______________ in order to coordinate successfully, while __________ can achieve successful coordination even on the basis of ____________.

A) randomly re-matched groups; exhortative messages; fixed groups; financial incentives.
B) randomly re-matched groups; financial incentives; fixed groups; exhortative messages.
C) randomly re-matched groups; communication; fixed groups; no communication.
D) randomly re-matched groups; exhortative messages; fixed groups; no communication.