Answer: Option B
Explanation: As we know that,
[tex]ROI=\frac{Operating\ income}{total\ assets}[/tex]
where,
Operating income = $60,000
total asset = current asset base - decrease in current asset base
total asset = $500,000 - $120,000
= $ 380,000
Now, putting the values into equation we get :-
[tex]ROI\:=\:\frac{\$60,000}{\$380,000}[/tex]
= 15.79%