The Treaty of Paris marked the end of the Spanish American War. The correct option among all the options that are given in the question is option "a" or the first option. The Treaty of Paris was signed on 3rd of September in the year 1783. I hope that this is the answer you were looking for and it has helped you.
The Soviets were setting up nuclear missiles in Cuba. This meant that they were now able in theory to launch a nuclear missile directly at large parts of the USA and it was therefore viewed as a threat by the USA. I hope that helps.
John Quincy Adams in what is called the "Corrupt Bargain" of 1824
It resulted in a stalemate which meant that the USA had a distant threat but still a threat it also resulted in a trading partner and a loyal Allie in the pacific area