The church was actually quite influential, and they decided what people would be informed and what they wouldn't be informed. People started realizing this so they didn't like this. The church was a big deal, so that takes out answer a, b and because they were such a big deal, they had money, so also d. Therefore the answer is C: Many priests were as poor as their parishioners.
During the Princes’ Crusade, late 1096-1099, the crusaders captured Constantinople.
I’m thinking they meant to put Constantinople instead of Jerusalem for answer C. And since that’s the only one that talks about capturing a city, the answer is C