The Thompson Company used standard costing and has established the following direct material and direct labor standards for each unit Lept. Direct materials: 2 gallons at $4.00 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 materials quantity variance for September was: a. $2,460 unfavorable b. $5,600 unfavorable c. $2,400 unfavorable d. 5,740 unfavorable