Canada Ltd reports that at an activity level of 20 000 units the maintenance cost is $24 000, and at 40 000 units the maintenance cost is $36 000. Using the high-low method, the cost formula for maintenance is: Select one: a. $12000 + $.1.54 x units. O b. $10 000 + $.60 x units. c. $12 000 + $.60 x units d. $1.54/unit e. Not one of the options Next page