Scandinavia,Northern Europe... hope it helps
The correct answer to this open question is the following.
Non-violent resistance can be successful because it is a powerful way to show discontent to any injustice or support to another valid issue, conveying the message that violence is no need to unite people against the support of a common cause. Non-violent demonstrations and protests have demonstrated to be so powerful to make changes in different places of the world.
The examples of non-violent resistance that you have learned about are the cases of Mahatma Gandhi, the pacifist leader in India, who was the first to use non-violent demonstrations. Another good example would be Dr- Martin Luther King Jr, who supported non-violent demonstrations such as the March to Washington.
The issue that I feel non-violent resistance could encounter and limit success is that people cannot defend themselves in the case of police aggression or other types of aggression, such as another group who favor violence to stop those pacifist demonstrations.
Here I have attached a photo to help you with this:
The correct answer is A) reduced tensions with the Soviet Union and signed treaties to limit nuclear weapons.
When Nixon was President, the US and Soviet Union signed the Strategic Arms Limitation Treaty (aka SALT) in 1972. This treaty specifically limited the amount of long-range missiles available to both countries as well as the amount of balistic missiles with nuclear weapons. This period of detente significantly decreased the probability of nuclear war between these two countries.