Answer: The correct answer is "a) true".
Explanation: All firms maximize profits by producing an output level where marginal revenue equals marginal cost; for firms operating in perfectly competitive industries, maximizing profits also means producing an output level where price equals marginal cost. IS TRUE.
Companies maximize profits by producing to the point where marginal income is equal to marginal cost because this means that the cost incurred to produce one more unit of production is less than or equal to the income generated by producing that unit. In perfect competition, companies are accepting prices, therefore companies will have a constant marginal income that will be equal to the price, maximizing profits at a production level in which :
MARGINAL INCOME = PRICE = MARGINAL COST.