5. What does the term "relevant range" mean? A. The range within which costs may fluctuate. B. The range within which a particular cost formula is valid. C. The range within which production may vary. D. The range within which the relevant costs are incurred. 6. Anaconda Mining Company shipped 9,000 tons of copper concentrate for $450,000 in March and 11,000 tons for $549,000 in April. Use the high-low method to estimate the shipping costs for 12,000 tons to be shipped in May. A. $548,780. B. $549,020. C. $594,000. D. $598,500. 7. Once the break-even point is reached, which of the following statements is true? A. The total contribution margin changes from negative to positive. B. Operating income will increase by the unit contribution margin for each additional item sold. C. Variable expenses will remain constant in total. D. The contribution margin ratio begins to decrease