Chiodini Incorporated has a $900,000 investment opportunity that involves sales of $2,430,000, fixed expenses of $1,044,900, and a contribution margin ratio of 50% of sales. The return on investment (ROI) for this year's investment opportunity considered alone is closest to:

A) 16.3%
B) 18.9%
C) 7.0%
D) 135.0%

To calculate ROI, we need to divide the net profit by the cost of investment and multiply by 100.

First, let's calculate the variable expenses using the contribution margin ratio:

Contribution Margin = Sales - Variable Expenses

0.5(Sales) = Sales - Variable Expenses

0.5(Sales) = $1,215,000

Sales = $2,430,000

Variable Expenses = $2,430,000 - $1,215,000 = $1,215,000

Now, let's calculate the net profit:

Net Profit = Sales - Variable Expenses - Fixed Expenses

Net Profit = $2,430,000 - $1,215,000 - $1,044,900 = $169,100

Finally, let's calculate ROI:

ROI = (Net Profit / Cost of Investment) x 100

ROI = ($169,100 / $900,000) x 100

ROI = 18.79%, which is closest to 18.9%. Therefore, the answer is B.