PNB Cos Has Sales of $250,000 and Cost of Goods Sold

PNB Cos. has sales of $250,000 and cost of goods sold of $120,000. The firm had a beginning inventory of $19,000 and an ending inventory of $13,000. What is the length of the days' sales in inventory?

A) 27.74 days
B) 57.79 days
C) 18.98 days
D) 39.54 days