Final answer:
The correct answer is c) Comitatus, which is the Germanic structure where kings consulted with their warriors, forming a personal alliance known as a warband, and distinct from the feudal system.
Step-by-step explanation:
Germanic Friendship Structure in Kingship
The Germanic friendship structure that compelled kings to rule in consultation with their warriors and formed a warband is known as comitatus. This concept is rooted in the Germanic world where warrior loyalty was paramount, and the king was expected to consult and provide for his warband. In contrast to feudalism, which emerged later as a hierarchal system where lords granted lands to vassals in exchange for military service, comitatus was characterized by more personal ties of allegiance between a leader and his men. This structure was essential for maintaining power and ensuring mutual protection and support. In the context of the provided options, chivalry refers to the medieval knight's code of conduct, and serfdom describes the condition of peasants who were bound to the land and could not leave their lord's estate permission.