X Company currently buys a part from a supplier for $12.63 per unit but is considering making the part itself next year. Estimated costs to make the part next year are: Per-Unit Total Direct materials $3.20 $9,600 Direct labor 3.90 11,700 Variable overhead 2.70 8,100 Fixed overhead Total 4.00 $13.80 12,000 $41,400 Of the estimated fixed overhead, $6,000 are common costs that would be allocated to the part; the remainder would be additional fixed overhead costs. X Company currently receives $2,600 a year by renting out unused factory space, but it will have to use this space to make the part. This year, they purchased 3,000 units of this part, but they're not certain how many units they will need next year. How many units will make them indifferent between continuing to buy the part and making it? A: 3,039 OB: 3,799 OC: 4,748 OD: 5,935 OE: 7,419 OF: 9,274