When Mary plays guitar for three hours, and her grade on the French test is 90 percent. Last week, after playing for three hours, Mary considered playing guitar for a fourth hour. She decided to play for one additional hour and cut her study time by one hour, but her French grade fell to 70 percent. What can you conclude about Mary's marginal benefit and marginal cost of the third hour of playing guitar? Question content area bottom Part 1 A. The marginal benefit from the third hour of playing guitar exceeded the marginal cost of dropping 20 percentage points on a French test. B. The marginal benefit from the third hour of playing guitar exceeded its marginal cost. C. The drop of 20 percentage points on a French test exceeded the marginal benefit from a fourth hour of playing guitar. D. The marginal cost of the third hour of playing guitar exceeded its marginal benefit