Originally considered by economist Robert Mundell, decades later, in 2001, Europe adopted a new common currency now known as:

The most important characteristic of the equilibrium price is that it: a. guarantees that producers earn profit. b. clears the market

c. increases the quantity demanded. d. decreases the quantity demanded.

Refer to the data for a nondiscriminating monopolist. At its profit-maximizing output, this firm's total costs will be:

A.  $300.
B.  $248.
C.  $198.
D.  $126.