im told that D is the correct answer but I keep getting 2200 ??

24. Windstar Corp. purchased supplies at a cost of $6,000 during the year. At December 31, supplies on hand are $1,400. Supplies expense for the year was $5,200. How much were supplies on hand at January 1? a. $2,200 b. $ 11,200 c. $ 1,400 d. $ 600