D&R Corp. consumes 300,000 units of spare part V per year. The average purchase lead time is 20 working days while the maximum is 27 working days. The company's annual operations cover 240 days allowing for shutdowns for plant maintenance, holidays and Sundays. The company would like to keep safety stock or extra stock to guard against stock- outs. How much is the safety stock? (Show in a good accounting form). a. 25,000 units. b. 1,250 units. C. 33.750 units. d. 8,750 units