Final answer:
The statement regarding a fief being land held on the conditions of feudal service is true. The feudal system involved an exchange of land for military and other services, with serfs working the land and vassals providing loyalty to their lords. Therefore, the most appropriate option is A.
Step-by-step explanation:
A fief is indeed an estate of land, especially one held on condition of feudal service. This statement is True. The feudal system was a social and economic structure that flourished during the Middle Ages in Europe. Lords would grant land, or fiefs, to vassals in exchange for military service and other forms of fealty. The vassals had the right to work the land and benefit from its productivity, while owing protection and support to the lord. Over time, feudalism paved the way for the rise of a more centralized state, especially as the bureaucracy expanded and royal authority solidified. This system also involved the Church, which became a powerful and wealthy landowner. It also included the serfs, who were agricultural laborers, bound to the land, and responsible for its upkeep, providing the economic foundation of this feudal society. The rights and privileges inherent in this system were, in theory, overseen by a king, who acted as the ultimate guarantor.