A lamp store purchased $3,100 of lamps in September. The store had $1,900 of lamps on hand at the beginning of September, and expected to have $1,400 of lamps at the end of September to cover part of anticipated October sales. What is the budgeted cost of goods sold for September? O A. $6,400 O B. $5,000 O C. $2,600 O D. $3,600