The "Emancipation Proclamation" issued by President Lincoln as the Civil War came to a close declared slaves were to be freed throughout the entire US.
This is probably biological warfare because it's not allowed according to the Geneva congress. Using poisons, toxic matters, viruses and bacteria, as well as flamethrowers and things like that are forbidden or else it will be considered a war crime and people will answer for it. It was practiced in World War 1 but was forbidden after.
The only correct answer can be statement C.
The British and the America colonists work together to defeat the French in the French and Indian War, showing that statement A cannot be correct.
One result of the French and Indian War was France giving up a large amount of territory to the British. This included a significant part of modern day Canada. This shows that statement B is wrong.
Statement D is also incorrect because the French lost land.
This shows how only statement C. can be correct.
During the cold war the US and Russia both had nuclear weapons because If one side decided to attack the other it was ensured that the other would see equal or even more destruction. Basically the mutually assured destruction or MAD deterred people from attacking because they knew they would be destroyed aswell in turn. Preventing military conflict by the mutual understanding that if you provoke or attack us it wont be to far away from us attacking you back