The 45-degree line equates the level of income measured on the horizontal axis to the level of consumption plus saving measured on the vertical axis

The total social cost of production is equal to

A) external cost minus internal cost. B) internal cost minus external cost. C) external cost plus internal cost. D) internal cost plus opportunity cost.

If a competitive firm is currently producing a level of output at which marginal cost exceeds marginal revenue, then

a. a one-unit increase in output will increase the firm's profit. b. a one-unit decrease in output will increase the firm's profit. c. total revenue exceeds total cost. d. total cost exceeds total revenue.