Final answer:
The correct answer is b) Manor. The manor refers to a lord's estate, which included lands worked by peasants as part of the feudal system.
Step-by-step explanation:
The farm estate that the lord owned and the peasants worked is known as a manor (option b). This system, part of the wider feudal system, involved the distribution of land in exchange for service and protection. The lord of the manor had the responsibility to protect the serfs and administer their work.
In return, serfs had to work the land and provide services for the lord, such as farming the lord's fields and paying rent, often in the form of a portion of their harvest. The manorial system was characterized by manorialism, which was prevalent in medieval Europe, where most people lived in rural areas and society was overwhelmingly agrarian.