Given the Financial Data for Four Mutually Exclusive Alternatives in the Table

Given the financial data for four mutually exclusive alternatives in the table below, determine the best alternative using the incremental rate of return (?RoR) analysis. MARR =10%.
$$\begin{array} { | l | l | l | l | l | } \hline & \text { A } & \text { B } & \text { C } & \text { D } \\\hline \text { First cost } & \$ 15,000 & \$ 36,000 & \$ 21,200 & 45,000 \\\hline \text { O \&M Cost/year } & 1,600 & 400 & 900 & 1,000 \\\hline \text { Benefit/year } & 8,000 & 13,000 & 9,000 & 15,000 \\\hline \text { Salvage value } & 3,000 & 6,000 & 4,600 & 10,000 \\\hline \text { Life in years } &&& { 4 } \\\hline\end{array}$$

A) Alt. A
B) Alt. B
C) Alt. C
D) Alt. D