The standard costs and actual costs for factory overhead for the manufacture of 3,000 units of actual production are as follows: Standard Costs Fixed overhead (based on 10,000 hours) 3 hours per unit @ $0.70 per hour Variable overhead 3 hours per unit @ $2.01 per hour Actual Costs Total variable cost, $18,000 Total fixed cost, $7,900 The total factory overhead cost variance is

a.$-90 unfavorable

b.$610 unfavorable

c.$1,310 favorable

d.$610 favorable