Star Footwear Inc. produces casual shoes that use a leather as the main raw material. The following is the data for May related to the shoes: Standard quantity per unit of output (yards). Standard Price (SP) per yard Actual materials purchased in yards Actual cost of materials purchased Actual materials used in production (yards) Actual outputs in units 2.5 $10.5 19,500 $80,100 6,000 3,200 What is the materials quantity variance for leather for May? OA. $141,750 unfavorable OB. $141,750 favorable OC. $21,000 unfavorable OD. $21,000 favorable