Casteel, Inc., manufactures a single product in which variable manufacturing overhead is assigned on the basis of standard direct labor- hours. The company uses a standard cost system and has established the following standards for one unit of product: Standard Quantity Standard Price or Rate Standard Cost Direct materials 1.5 pounds $3.00 per pound $4.50 Direct labor 0.6 hours $6.00 per hour $3.60 Variable manufacturing overhead 0.6 hours $1.25 per hour $0.75 During March, the following activity was recorded by the company: The company produced 2,000 units during the month. A total of 6,000 pounds of material were purchased at a cost of $23,000. There was no beginning inventory of materials on hand to start the month; at the end of the month, 3,900 pounds of material remained in the warehouse. During March, 1,600 direct labor-hours were worked at a rate of $6.50 per hour. Variable manufacturing overhead costs during March totaled $1,800. The direct materials purchases varience is computed when the materials are purchased. The materials quantity variance for March is: O a. $-2,700.00 O b. $20,700.00 O c. $-5,400.00 O d. $41,400.00