Context: American cheese, Cheez Whiz, and provolone are the most commonly used cheeses or cheese products put on to the Philly cheesesteak.

Question: what kinda cheese is on a philly cheesesteak?
Steam of consciousness below:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
The relevant information to answer the above question is: American cheese, Cheez Whiz, and provolone are the most commonly used cheeses or cheese products put on to the Philly cheesesteak.
So, the answer is American cheese.