In a monopoly, when abnormal profits are made

The price set is greater than the average cost
The price is less than the marginal cost
The average revenue equals the marginal cost
Revenue equals total cost

The correct answer is A. The price set is greater than the average cost.

A monopoly is a market structure in which there is only one seller of a good or service. This means that the monopolist has a great deal of market power and can set prices without fear of competition. As a result, monopolies are often able to charge prices that are higher than the marginal cost of production, which leads to abnormal profits.

The average cost is the total cost of production divided by the number of units produced. The marginal cost is the additional cost of producing one more unit. In a monopoly, the marginal cost is usually lower than the average cost. This is because the monopolist can spread the fixed costs over a larger number of units. As a result, the monopolist can make abnormal profits by charging a price that is greater than the average cost.

Option B is incorrect because the price is less than the marginal cost. This would mean that the monopolist is losing money.

Option C is incorrect because the average revenue equals the marginal cost in a perfectly competitive market. A monopoly is not a perfectly competitive market.

Option D is incorrect because revenue does not equal total cost in a monopoly. The monopolist makes abnormal profits, which means that revenue is greater than total cost.