Melissa's Dress Shop's Inventory at Cost on January 1 Was

Melissa's Dress Shop's inventory at cost on January 1 was $19,400. Its retail value was $36,000. During the year, additional net purchases at a cost of $42,600 were brought in. Its retail value was $64,000. The net sales for the year were $70,000. Melissa's inventory at cost by the retail method is:

A) $30,000
B) $18,600
C) $18,000
D) $12,400
E) None of these