14. Average maintenance costs are $1.50 per machine hour at an activity level of 8,000 machine hours and $1.20 per machine hour at an activity level of 13,000 machine hours. Assuming that this activity is within the relevant range, total expected maintenance cost for a budgeted activity level of 10,000 machine hours would be closest to which of the following? A) $13,440 B) $11,433 C) $16,128. D) $15,000. HL