Relationships Between Vassals and Lords Included All of the Following

Multiple Choice

Relationships between vassals and lords included all of the following except

A) The vassal owed the lord unlimited military service
B) Lords owed land and military protection to vassals
C) The lord-vassal relationship gradually became hereditary, reducing the control of the lord over his vassals
D) The lord-vassal relationship was considered contractual and could be voided if either side breached the agreement