Production line workers at Clarkson Enterprises worked a total of 5.000 direct labor hours to produce 10,000 mirrors in April. The standard for producing the mirrors allows 24 minutes per mirror at a wage rate of $10 per hour. If the actual wage rate was $11 per direct labor hour, Clarkson's direct labor efficiency variance for April was 0 $5,000 U. O $5,000 F 0 $10,000 U. O $10,000 F