Answer:
The correct answer is the option A: the marginal revenue curve and the demand curve are the same.
Step-by-step explanation:
To begin with, the concept of ''perfectly competitive market'' refers to the market where there are a lot of firms and their products are exactly the same with no differentation, therefore that they can not establish an influence in the price. In addition to that, in this type of market the equilibrium is in the point where the marginal revenue equals the marginal cost and in this case where there is no influence from the firms then the price of the product will be established by the demand itself and therefore that also the marginal revenue of the firm as well.