9. Joe is in training, hoping he will make the varsity football team next season. He will usually train for five hours a day, four days a week. On the last day of training before tryouts, Joe decides to train one extra hour. Joe's decision is worth it if which of the following is TRUE?
A. Joe should continue training for an extra hour if he thinks the extra practice will help him get on the team.
B. Joe should continue training an extra hour if the marginal cost is greater than the marginal benefit.
C. Joe should continue training an extra hour if the marginal benefit is greater than the marginal cost.
D. Joe should not continue training an extra hour, because the opportunity cost is too great.
E. Joe should not continue training an extra hour, because the opportunity cost is equal to the decision to train.
12. The production possibilities curve will show a straight line if which of the following is TRUE?A. The opportunity cost is constant.B. Vital resources for the good are limitless.C. The economy is operating below maximum efficiency and output.D. The law of decreasing marginal utility does not apply.E. Marginal benefit is less than marginal cost.