Quaker State has established the following direct material and direct labor standards for each unit of synthetic oil in its standard costing system. Direct materials: 2 gallons at $4 per gallon Direct labor: 0.5 hours at $8 per hour During September, the company made 6,000 units of synthetic oil 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 57.65 per hour The materials price variance for September was: a) $1,340 favorable b) $1,260 favorable c) \$1,340 unfavorable d) $1,260 unfavorable