cow chip cookies, a giant cookie company, has been fairly successful in its market. lydia sees an opportunity for profit and enters the market. after producing her profit-maximizing level of output, she finds that her average total cost per unit is $3, her average variable cost per unit is $2, and the market price is $2.50. in the short run, lydia should choose one: a. shut down her business. b. expand production because she is making a positive economic profit. c. stay in business even though she is suffering a loss.