Consider a firm with an annual net income of $30 million, revenue of $70 million and cost of goods sold of $35 million. If the balance sheet amounts show $3.5 million of inventory and $800,000 of property, plant & equipment, what is the inventory turnover?

a. 12.50
b. 4.44
c. 17.50
d. 5.00
e. 10.00