Final answer:
In a perfectly competitive market, firms must charge the market price for their products because there are many other firms producing identical products.
Step-by-step explanation:
In a perfectly competitive market, homogeneity means that firms must charge the market price for the goods or services they produce, because there are many other perfectly good firms producing identical products.
In perfect competition, there are numerous sellers offering the same products to many buyers. Since the products are identical, buyers have no reason to pay more for one seller's product over another. Therefore, each firm is a price taker and must charge the market price.
For example, in an agricultural market where all farmers produce the same type of apples, each farmer must sell at the prevailing market price, as customers have no incentive to pay a higher price for one farmer's apples when they can get the same quality at a lower price from another farmer.