The answer would be B-the real reason reason Rome fell
The Berlin Blockade<span> (24 June 1948 – 12 May 1949) was one of the first major international crises of the </span>Cold War<span>. During the </span>multinational occupation of post–World War II Germany<span>, the </span>Soviet Union<span> blocked the </span>Western Allies<span>' railway, road, and canal access to the sectors of </span>Berlin<span> under Western control. The Soviets offered to drop the blockade if the Western Allies withdrew the newly introduced </span>Deutsche mark<span> from </span>West Berlin<span>.</span>
Answer:
With the Discovery of trench warfare, There was a need for weapons that were capable of long-range destruction and also inflict maximum damage at the same time. this resulted in the invention of many new weapons.
I believe the answer is the United States.