A. They were regarded as the property of the noble whose fields
they worked.
Explanation:
Serfdom represented a set of legal norms enshrining a prohibition for peasants leaving their land allotments without the permission of the authorities (that is, peasants attached to the land; runaways were subject to forced return), hereditary subordination of administrative and judicial authorities of a certain feudal lord, depriving peasants of the right to alienate land plots and acquire real estate, sometimes - an opportunity for the feudal lord to alienate peasants without land. In its most severe manifestations, serfdom is approaching slavery.