Use this information to answer the question that follow. 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 @ $0.72 per hour 3 hours per unit @ $1.99 per hour Variable overhead Actual Costs Total variable cost, $18,000 Total fixed cost, $8,100 The total factory overhead cost variance is Oa. $2,436 unfavorable b. $1,284 unfavorable Oc. $3,588 favorable d. $2,436 favorable