Answer:
D)
Step-by-step explanation:
D) Both of these. World War I was a major conflict that took place between 1914 and 1918. It involved many of the world's great powers, and resulted in millions of deaths and injuries. The war demonstrated for the first time the destructive power of modern technology, as well as the psychological effects of the conflict on soldiers. As a result, the idea of the heroic soldier was fundamentally changed.