The correct answer is C. 2.50 . The CSSBB financial-measures material gives the widely used formula:

ROI = Net Income / Investment

To apply that formula correctly, the net income or project gain is the savings minus the investment :

Net income = 700,000 − 200,000 = 500,000

Then divide by the investment:

ROI = 500,000 / 200,000 = 2.50

So the project returns 2.5 times the invested amount , which matches option C . This is consistent with Six Sigma project financial evaluation, where costs and benefits are compared to determine whether the project is worthwhile and how strongly it contributes to profitability. The CSSBB source also emphasizes that financial benefits are used to evaluate, prioritize, select, and track Six Sigma projects.

Option D would result only if someone incorrectly divided total savings by investment without subtracting the investment itself. Under the CSSBB ROI definition using net income, the verified answer is 2.50 .