If you received a free month's trial membership in a gym, you would keep going until your marginal utility reached

An aggregate supply curve may be horizontal over some range because within that range

A) a higher price level leads to higher interest rates, which reduce the money supply and consumer spending B) changes in the aggregate price level do no induce substitution C) output cannot be increase unless prices and interest rates increase D) rigid prices prevent employment from fluctuating E) resources are underemployed and an increase in demand will be satisfied without any pressure on the price level

The use of money

A. reduces the transaction costs of exchange B. eliminates the double coincidence of wants C. Allows for greater specialization D. All of the above