Suppose That for the Past Two Months, You Have Studied

Multiple Choice

Suppose that for the past two months, you have studied economics one hour a day. You now decide to study economics two hours a day. For the past two months

A) your marginal cost of studying economics for an hour must have exceeded its marginal benefit.
B) the marginal cost of studying economics must have fallen.
C) your marginal benefit from studying economics an hour must have been greater than its marginal cost.
D) the opportunity cost of studying economics must have risen.