Recreation Equipment Company Has Several Divisions Which Are Investment Centers

Recreation Equipment Company has several divisions which are investment centers. Data for the Boat Division and the Trailer Division are shown here:
$\begin{array}{|l|r|r|}\hline & \text { Boat Division } &{\text { Trailer Division }} \\\hline \text { Operating income } & \$ 90,000 & \$ 36,000 \\\hline \text { Total assets at Jan 1 } & \$ 670,000 & \$ 230,000 \\\hline \text { Total assets at Dec } 31 & \$ 710,000 & \$ 220,000 \\\hline\end{array}$
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How much is the ROI of the Boat Division?

A) 12.7%
B) 12.8%
C) 12.9%
D) 13.0%