Keith, the intern, was given some information from his supervisor. The supervisor wants him to figure out how well her department is doing. Keith suggests using Return On Investment as a gauge. The figures include: Sales of $250 000, Net Operating Income of $30 000, Average Operating Assets of $200 000, and the company's required return is 12%.

What is Keith's Department's Return on Investments?

a) 12% b) 60% c) 1.5% d) 15%