-people wanted to move because they wanted better lives. they faced dangerous journeys .
-they moved west because land was cheap or free and they thought they would do better business in the west .
-people who weren't making business or wasn't making any money, found the opportunities to move west to start everything all over again
The correct answer is: -With nuclear weapons, it would be too destructive
In essence, an open war between the two nations would be a nuclear war and no one could stomach that instant destruction.
I believe c i hope this helps!
The one that you have picked is correct