The above figure shows the market for steel ingots. The socially optimal quantity of steel is

The vertical distance between total cost curve and total variable cost curve is equal to

A) average fixed cost. B) total fixed cost. C) average variable cost. D) average total cost. E) marginal cost.

Understanding economics would be helpful to which of the following individuals?

a. a college student planning her next semester courses b. a fashion designer selecting fabric for a new spring collection c. a restaurant owner deciding whether to expand his establishment's hours of operation d. All of the above