In what way did the Christian Crusades contribute to the decline of the Byzantine Empire?

A: Financing the Crusades proved to be an impossible burden for the Byzantine treasury.

B: Latin Crusaders turned against the Byzantines, leading to the loss of much territory.

C: The Byzantine army lost many of its leading knights when they left to fight in the Crusades.

D: Nations that were not joining the Crusades attacked Byzantium when it was occupied in the east