The correct option is B The duty of the noblemen was to protect the vassals and the vassals were meant to offer services in return.
The influential individuals who came to acquire land as a result of the king's grants were called the noblemen. These noblemen then went on to give portions of these lands to individuals called vassals. It was the duty of the noblemen to protect the vassals, while the vassals were meant to offer services to the noblemen in return. Feudalism was thus, based on a system of mutual give and take. This system resulted in the creation of a political and economic hierarchy between the king, the noblemen, and the farmers.