The answer is : The crusades.
The Crusades were a series of religious wars between Christians and Muslims started primarily to secure control of holy sites considered sacred by both groups. In all, eight major Crusade expeditions — varying in size, strength and degree of success — occurred between 1096 and 1291.
Answer: Vikings, Muslims, and Magyars invaded Europe at a time of political weakness.
Explanation:
Feudalism refers to a system where the King or Queen was the absolute monarch and as a result owned all the land but could give it to Nobles who would then become rich and powerful.
This system was as a result of people needing such protection that they bounded around the Nobles to protect them when invasions from groups such as the Vikings, the Muslims and the Magyars threatened their security in a way the monarchs could not effectively protect them.
All organized communities have government, leadership, form of currency or trade, and citizens, etc. Hope this helps.
A, because it explains a lot of the reason everything happened
The fall of the twin towers and the death of million
