Answer:
D, It was a failure because Christian armies failed to gain full control of Jerusalem.
Step-by-step explanation:
Most of the Crusaders were utter failures, because everybody hated the Crusaders, even they're fellow Christians. We know B is wrong, because Jews didn't fight in the battle, they were mainly mercenaries working for the Islamic Caliphates. C is wrong, because Jerusalem was under Muslim control until recently when the State of Israel was created.