Which term identifies a medieval political hierarchical system with a king at the top level, then his vassals, and serfs on the lowest level? feudalism bushido chivalry manorialism

The correct answer is A.
Feudalism is a political system which was prevalent in Europe between the ninth and fifteenth centuries. The majority of privileges and rights were offered to the Upper class and level of the society. The King ruled and owned everything and had total control over all. His vassals (knights) were given some small parts of land but in exchange, they had to provide military protection. The serfs were lent land and they had to provide food and services to the upper classes. 

Iwould pick a true