Instruments of US foreign policy
The United States pursues its four main foreign policy goals through several different foreign policy types, or distinct substantive areas of foreign policy in which the United States is engaged. These types are trade, diplomacy, sanctions, military/defense, intelligence, foreign aid, and global environmental policy.
Probably 1, however I can see why that would be a tiny bit confusing.
Building walls protects from incoming invaders(at least back in the day), creating armies, makes a force to go and fight to protect the people, and what was the other one? Oh yea, moving to a safer place.
Doing that would mean making invasions less likely, and making your people feel and be safer.
Hope this helps.
Its A. Create laws hope it helps