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?

10,000 9,000 Profit = Q(P - AC) Price, marginal cost ($) 8,000 C (8, 7500) 7,000 Marginal cost 6,000 A (35, 6000) Isoprofit curve: $150,000 5,000 Isoprofit curve: $70,000 4,000 Zero-economic-profit curve (AC curve) 3,000 B (40, 3300) 2,000 1,000 0 0 10 20 30 40 50 60 70 80 90 100 110 120 Quantity of cars