On average, a firm sells $2,500,000 in merchandise a month. Its cost of goods sold equals 60 percent of sales, and it keeps inventory equal to one-half of its monthly cost of goods on hand at all times. If the firm analyzes its accounts using a 360-day year, what is the firm's inventory conversion period?

	a.	20 days
	b.	360 days
	c.	30 days
	d.	10 days
	e.	15 days