The diagram illustrates isoprofit curves and the marginal cost curve of MQ2020, a luxury car manufactured by MQ
Motors. Which statement incorrectly describes the diagram?
a. An isoprofit curve traces the combinations of price and quantity that give the same profit.
b. If MQ Motors sells 40 cars at P=$4,000, it will make negative economic profit.
c. Points B and C give MQ Motors the same level of profit.
d. If MQ Motors sells 35 cars at P=$6,000, it makes profits larger than $70,000.
e. MQ Motors incurs increasing marginal cost.