Hassock Corp. produces woven wall hangings. It takes 2 hours of direct labor to produce a single wall hanging. Bartels' standard labor cost is $12 per hour. During August, Bartels produced 10,000 units and used 21,040 hours of direct labor at a total cost of $250,376. What is Bartels' labor efficiency variance for August? $12,480 favorable. $10,376 unfavorable. $14,584 unfavorable. $4,160 favorable. $12,480 unfavorable.