Answer:
c. depend on both how much output it produces and how much output its rival firms produce.
Explaination:
Oligopoly is a small number of interdependent large firms that dominate the market. It has significant barriers to entry (e.g. trade secrets, high start-up costs, and heavy advertising to create brand image).
In oligopoly, there is a non-price competition, also, products may be differentiated (e.g. cars, aircrafts, etc.). Firms make economic profits. They are Interdependent (not independent; the actions of one firm will affect the other, which is why sometimes they make agreements in secret). Here,Prices are sticky (do not change a lot).