QUESTION 14 Denver, Inc, believes that its maintenance costs behave as a mixed cost. The firm's highest maintenance cost was $3,600 in May when the firm made 500 units, and the lowest maintenance cost was $2,800 in August when the firm made 200 units. What was the variable cost per unit associated with the firm's maintenance costs? (Round your answer to the nearest cent.) A. $7.20 per unit 8. $14.00 per unit C. $2.67 per unit D. $4.00 per unit