1. The opportunity cost of going to college for a student receiving a scholarship
A. is the risk of dropping out.
B. is the food and living expenses that she has to purchase while in college.
C. is zero because she does not have to pay tuition.
D. is the income that she would have earned if she did not go to college.
2. Spending more time commuting in exchange for a lower monthly rent refers to? a(n):
A. monetary exchange.
B. barter.
C. ?trade-off.
D. externality.
3. Suppose biochemists discover an enzyme that can double the amount of ethanol that may be derived from a given amount of biomass. Based on this technological? development, we expect? the:
A. demand curve for ethanol to shift leftward.
B. demand curve for ethanol to shift rightward.
C. supply curve for ethanol to shift leftward.
D. supply curve for ethanol to shift righward.