How can firms use marginal analysis to determine the price of a product?

Firms can use marginal analysis to dispose the price so the profit maximization occurs. They can reach that from the analysis of fixed costs, variable costs and knowing the real price of the product in the market. Keep in mind that if the total of the costs is very close to the price of the product in the market there will be no profits.

Its C. Examining the effect on revenue of small changes to the price of one item