Answer:
The answer is all of the above
Step-by-step explanation:
The crusades which happened on the European society brought about so many changes in the life of people in that region and the environment at large. during the Crusades, so many lands were captured with the prominent being that of palestine that had a shortlived christian people living in it before the subsequent loss to islam.
It also encourages, the architectural method of building stone fortifications as can been seen in various ancient buildings and the unification of catholic and orthodox branches of christianity after the defeat of the warring parallel bishop. Also, it was in the period of the crusades on the European society that the most famous disease known as Bubonic plague (Black death) ravaged Europe.