22 The following data pertains to activity and maintenance costs for two recent years it of 10 uestion Activity level in units Maintenance cost Year 2 Year 1 12.000 8,000 $15,000 $12.000 Using the high-low method, the cost formula for maintenance would be Select one: O a $1.50 per unit Ob. $1.25 per unit Oc$3,000 plus $1.50 per unit O d. $6,000 plus $0.75 per unit