Assuming suppliers produce 75 lawnmowers per week:
a. this quantity is allocatively inefficient because the marginal cost of producing the last lawnmower exceeds the marginal benefit to consumers.
b. this quantity is allocatively efficient because the last lawnmower provides more benefits to consumers than alternative uses of the resources required to produce it.
c. this quantity is allocatively inefficient because the marginal cost of producing the last lawnmower is less than the marginal benefit to consumers.
d. this quantity is allocatively efficient because it requires producers to reduce the price of lawnmowers in order to sell all of the lawnmowers produced.