The Thompson Company uses standard costing and has established the following direct material and direct labor standards for each unit of Lept. Direct materials: 2 gallons at $4 per gallon Direct labor: 0.5 hours at $8 per hour During September, the company made 6,000 Lepts and incurred the following costs: Direct materials purchased: 13,400 gallons at $4.10 per gallon Direct materials used: 12,600 gallons Direct labor used: 2,800 hours at $7.65 per hour The labor rate variance for September was: Select one: O a. $1,530 unfavorable O b. $980 favorable c. $280 favorable O d. $980 unfavorable