Answer:
C All of the answers are correct
Step-by-step explanation:
A market structure is termed as oligopoly when there are very few suppliers in a market of so many buyers. For oligopoly, the profit is maximized where the marginal cost equals the marginal revenue. If the marginal cost curve shifts upwards, it means that it increases. In an attempt to increase the cost in one firm, all the consumers will shift to the other firms, in an attempt to increase output, a company will make lesser profit. In this case, it means that the company will have to make use of non-price methods to compete. Therefore, the correct answer is C as the above given answers are all correct.