Groom Company uses flexible budgets. At normal capacity of 16,000 units, budgeted manufacturing overhead is: $48,000 variable and $270,000 fixed. If Groom had actual overhead costs of $321,000 for 18,000 units produced, what the difference between actual and budgeted costs? A) $3,000 unfavorable B) $3,000 favorable C) $9,000 unfavorable D) $12,000 favorable