I was accepted for Political Science.. Am i allowed to change my major once i get there to something like Business or Marketing? Or possible double major?

I know at many schools you can change your major easily. I was wondering that since i was accepted Poly Sci to arts and sciences, if i was somehow restricted to double majoring with something in the business school, or changing my major to something in the Bschool? I am not 100% gonna do this, its just a hypothetical. Can someone shed light on this process?

To be 100% clear. I was maybe thinking to double major with poly sci and Marketing, or something like that.