Final answer:
A vassal was obligated to give their loyalty to their lord primarily because the lord provided them with land, which was the basis of feudal obligations and mutual support in medieval Europe. The vassal pledged to serve militarily in exchange for this land grant, and this exchange was essential for the stability and structure of feudal society.
Step-by-step explanation:
Why was a vassal obligated to give their loyalty to their lord? In the context of feudal Europe, the mutual obligation between a lord and vassal was primarily centered on the provision of land and protection. A lord granted a vassal a fief, which was a portion of land, in exchange for the vassal's military service and other forms of support. This system, rooted in the feudal society of medieval Europe, established a strict hierarchical order based on land ownership and the fulfillment of mutual obligations. The pledge of fealty by the vassal to the lord ensured stability within this system - one that was often tumultuous and marked by power struggles and the need for security against various threats. The correct answer to the question is B. The lord gave the vassal land. This land grant enabled the vassal to extract resources, typically from the peasants working the land, which in turn allowed the vassal to afford the necessities of warfare and fulfill the military duties owed to the lord. While there were certainly instances of coercion and threats within feudal relationships, the primary reason for a vassal's loyalty was the land grant that came with the expectation of service and protection, not the other, more coercive options listed.