Sentence Correction

The olympic Games helped to keep peace among the pugnacious states of greek world in that a sacred truce was proclaimed during the festival's month.

A) world in that a sacred truce was proclaimed during the festival's month
B) world, proclaiming a sacred truce during the festival's month
C) world when they proclaimed a sacred truce for the festival month
D) world, for a sacred truce was proclaimed during the month of the festival
E) world by proclamation of a sacred truce that was the month of the festival