Explain how each of the following illustrates one of the four principles of individual choice.

a. You are on your third trip to a restaurant’s all-you-can-eat dessert buffet and are feeling very full. Although it would cost you no additional money, you forgo a slice of coconut cream pie but have a slice of chocolate cake.

b. Even if there were more resources in the world, there would still be scarcity.

c. Different teaching assistants teach several Economics 101 tutorials. Those taught by the teaching assistants with the best reputations fill up quickly, with spaces left unfilled in the ones taught by assistants with poor reputations.

d. To decide how many hours per week to exercise, you compare the health benefits of one more hour of exercise to the effect on your grades of one fewer hour spent studying.