(answer asap i really need to get this test ) which describes the reason for hardship in the muslim world during the time of the european middle ages? a. christians from the byzantine empire continually tried to convert muslims to christianity. b. muslim nobles subjected most muslims to a miserable, difficult life of serfdom. c. european crusaders, attempting to win back jerusalem, enslaved most of the muslim world. d. mongol armies from central asia repeatedly invaded and conquered parts of the muslim world.