The standard costs and actual costs for factory overhead for the manufacture of 2,800 units of actual production are as follows: Standard Costs Fixed overhead (based on 10,000 hours) 3 hours per unit @ $0.77 per hour Variable overhead 3 hours per unit @ $2.00 per hour Actual Costs Total variable cost, $18,000 Total fixed cost, $8,100 The amount of the total factory overhead cost variance is a. $1,200 unfavorable b. $3,664 favorable c. $2,432 favorable d. $2,432 unfavorable