Refer to Figure 3-7. Assume that the graphs in this figure represent the demand and supply curves for frozen yogurt. Which panel describes what happens in the market for frozen yogurt when the price of ice cream, a substitute product, increases?

Rational economic decision makers will make a change only if

a. the change is free of risk b. there are no costs involved c. their expectations are correct d. there is no uncertainty about the results of the change e. the expected marginal benefit exceeds expected marginal cost

Normal profit is defined as

a. accounting profit b. economic profit c. profit necessary to ensure that opportunity costs are covered d. accounting profit minus economic profit e. economic profit minus accounting profit