Rocket Inc. provides the following standard cost data per unit of product: Direct material (3 gallons @ $6 per gallon) Direct labor (2 hours @ $10 per hour) $18.00 $20.00 During the period, the company produced and sold 23,000 units, incurring the following costs: Direct material Direct labor 68,000 gallons 45,500 hours @ $5.90 per gallon @ $ 9.75 per hour The direct labor usage variance was: O $16,500 favorable. $15,000 unfavorable. $5,000 favorable. O $15,000 unfavorable