In the generic diagram for a monopoly, the firm's profits per unit of output are determined by the O vertical difference between the marginal revenue curve and the marginal cost curve at the quantity at which the demand curve intersects the average total cost curve. O vertical difference between the demand curve and the average total cost curve at the quantity at which the marginal revenue curve intersects the marginal cost curve O horizontal difference between the marginal revenue curve and the marginal cost curve at the quantity at which the demand curve intersects the average total cost curve. O horizontal difference between the demand curve and the average total cost curve at the quantity at which the marginal revenue curve intersects the marginal cost curve O intersection between the marginal revenue curve and the marginal cost curve