The following materials standards have been established for a particular product: Standard quantity per unit of output 5.1 grams Standard price $11.95 per gram The following data pertain to operations concerning the product for the last month: Actual materials purchased 6,800 grams Actual cost of materials purchased $86,360 Actual materials used in production 6,300 grams Actual output 1,000 units What is the materials quantity variance for the month? a. $15,240 U b. $6,350 U c. $14,340 U d. $5,975 U