The condition in circular-flow models whereby firms purchase all the goods not purchased by households is that

A negative value for the U.S. official reserve assets line in the balance of payments accounts means that

A) U.S. residents have sold more gold to foreigners than they bought. B) U.S. residents bought more gold from foreigners than they sold. C) the U.S. central bank has increased its holdings of foreign reserve assets. D) the U.S. central bank has decreased its holdings of foreign reserve assets.

The mutual interdependence that characterizes oligopoly arises because:

A. the products of various firms are homogeneous. B. the products of various firms are differentiated. C. each firm in an oligopoly depends on its own pricing strategy and that of its rivals. D. the demand curves of firms are kinked at the prevailing price.