The marginal cost of labor for a perfectly competitive firm is the

The above figure shows the marginal social benefit, marginal private cost and marginal social cost of producing steel. If the market is competitive and unregulated, how much steel will be produced?

A) 0 tons B) 2 tons C) 4 tons D) 8 tons

A profit-maximizing monopolist will receive zero profits when

A) the average total cost curve lies above the demand curve for all possible rates of output. B) the average total cost curve is tangent to the demand curve at the profit maximizing price. C) marginal revenue, marginal cost, and average total cost are all equal. D) a second firm enters the industry.