a. The persecution of other religions by Islamic leaders
Explanation:
The distinctly religious character of the empire of Islam had made it spread so quickly and so powerfully as it converted people in the territories they won and amassed massive armies out of them.
They were able to conquer Jerusalem and then reach Spain in a short period of time and they were to employ the same tactics in both the places.
The difference wast hat they persecuted Jews more in the Jerusalem and the Christians were given a bit more lax treatment in the Spanish territory but both were persecuted.
