I believe it s C!! hope that helps x
It was the second war of American independence.
After WWll many of the weapons were left, and the Russian leader Nikita Kruschev decided that the Soviet Union needed more defense. So, they put missles in Cuba. J.F. Kennedy forced Kruschev to remove the missles, but, the Cold War wasn't over. It was just the beginning. In the years that followed, many countries tried to frighten each other by showing off the strength of their weapons, Navy, etc. That is what caused the Cold War.
The correct answer is the second one. Mechanization reduced the need for farmers. With machines they didn't need to do as much work. This way farm life was easier.