If,at the Equilibrium Quantity in a Market,the Benefit of the Last

Multiple Choice

If,at the equilibrium quantity in a market,the benefit of the last unit produced just equals its marginal cost,_____

A) each firm earns a positive economic profit.
B) the market is said to have achieved productive efficiency.
C) the market is said to have achieved allocative efficiency.
D) the firms in the market are said to have achieved economies of scale.
E) each firm in the market incurs an economic loss.