The standard costs and actual costs for factory overhead for the manufacture of 2,500 units of actual production are as follows Standard Costs Fixed overhead (based on 10,000 hours) 3 hours per unit at $0.80 per hour Variable overhead 3 hours per unit at $2.00 per hour Actual Costs Total variable cost, $18,000 Total fixed cost, $8,000 The variable factory overhead controllable variance a. $3,000 unfavorable b. $2,000 unfavorable c. $3,000 favorable d. $0