Why did the islamic world suffer hardship during the 1200s and 1300s?

a.
christian soldiers of the byzantine empire forced muslims under their control to accept christianity or face death.

b.
mongol armies rode out of central asia to invade and conquer first one part and then another part of the muslim world.

c.
muslim tyrants kept their subjects in serfdom and poverty.

d.
western european kings sent armies to retake jerusalem and capture as many muslims as possible to use as slaves.

In 911, a group of vikings lead by rollo besieged paris and chartres. after a victory near chartres on 26 august, charles decided to negotiate with rollo. the talks were led by hervé, the archbishop of reims. this resulted in the treaty of saint-clair-sur-epte, which granted rollo and his soldiers all the land between the river epte and the sea. it also granted him brittany, "for his livelihood". at the time, brittany was an independent land which france had not been able to conquer. in exchange, rollo promised the king his loyalty and military assistance when needed. also rollo also agreed to be baptised and to marry gisela, the king's daughter. the territory given rollo is about the same as upper normandy.

The answer is b. the cultures would blend