It was led by a dictator.
B. Morse created the telegraph in the United States in 1837.
This oddly sounds like something Hitler would have said, so based off my current knowledge of History, I will say it is answer choice D if what that is trying to say is communism.
It meant that as soon as one country falls under communist control, another country would fall and so on. Vietnam at the time was split into North (communist) and South (being attacked by North) and the US didn't want communism to spread, reasoning that it might eventually come to the US if nothing was done.
