which of the following statements is correct? group of answer choices monopolies are guaranteed to earn an economic profit. monopolies have perfectly inelastic demand for the product sold. because a monopoly is the only firm in the market, its marginal revenue curve must be the same as the market demand curve. the market demand and the firm's demand are the same for a monopoly. because a monopoly is the only firm in the market, its supply curve is the same as the market demand curve.