12. The flexible-budget variance for materials is $5,000 (U). The sales-volume variance is $13,000 (U). The price variance for material is $31 000 (F). The efficiency variance for direct manufacturing labor is $7,000 (F). Calculate the efficiency variance for materials. A) $36,000 favorable B) $13,000 unfavorable C) $6,000 favorable D) $36.000 unfavorable