Answer:
A. New weapons reduced the need for knights and the social structure of feudalism
Step-by-step explanation:
The Hundred Years' War was a series of conflicts between England and France that lasted from 1337 to 1453. It was the longest military conflict in European history.
During this war, new weapons, such as gunpowder, firearms, and cannons were introduced, reducing the need for knights. Another important effect of the war was that it helped weaken the social and political structures of feudalism by shifting the power from feudal lords to monarchs and to common people.