I am making a FPS game, and I need to know how to make my enemy bots choose options while in gameplay, like switching weapons, hiding, retreating, attacking, and others.
From the very general nature of this and your other question it sounds like you're a beginner, so fair warning: you have a lot of learning ahead. You may want to start by looking into Behavior Trees, which you could implement in Unity by using AngryAnt's Behave.
There is a pretty sweet fps tutorial at unity3d.com.