The correct answer is C) Christianity
Why? Because Constantine caused the power vacuum and Pope Gregory I filled it.
The reason for the decline of the Heian Dynasty in Japan was "<span>Elite clans amassed most of Japan's lands into vast estates".</span>
A. Urban II
These incursions prompted the emperor of Byzantium, Alexius I Comnenus to send a delegation to Piacenza, Italy, asking Pope Urban II in March 1095 for help against the Turks. On November 27, 1095, in Clermont, France, Pope Urban II called for a crusade to help the Byzantines and to free the city of Jerusalem.
May 13, 1938 is when armistice Day was declared
