In the long run, any firm may enter or leave a perfectly competitive market

If the government passed a law designating sea shells as money, sea shells

a. would not be legal tender b. would not function as money because they would be unable to serve as a unit of account c. would not function as money because they would be unable to serve as a means of payment d. would not function as money because they would be unable to serve as a store of wealth e. would function as money as long as they were accepted in exchange for goods and services

If average fixed cost exceeds average variable cost, a firm should shut down in the short run

a. True b. False