25. ABC Company uses the high-low method to separate mixed costs into their fixed and variable components. During the past year, their highest level of activity was in October when they had 20,000 machine hours and $5,800 of maintenance costs, while the lowest level of activity was in March when they had 12,000 machine hours and $3,400 of maintenance costs. Using the high-low method, what is the variable cost per machine hour? A) 8,000 per machine hour B) $2,400 per machine hour C) $0.30 per machine hour D) $3.33 per machine hour