What Was the Main Reason Alexius Comnenus Asked Pope Urban

What was the main reason Alexius Comnenus asked Pope Urban II to use the church's communication network to recruit warriors for him?

A) The Byzantines were short on manpower,while Western Europe had a surplus.
B) Alexius had heard that Frankish warriors were especially strong and brave.
C) The Muslims holding the territory they had taken from the Byzantines were in disarray and vulnerable.
D) Improved communication from East to West made such a recruitment effort feasible for the first time.
E) He wanted to bring the West into the Orthodox Church.