The Following Data Are for a Series of Increasingly Extensive

Multiple Choice

The following data are for a series of increasingly extensive ?ood-control projects. $$\begin{array} { | l | c | c | } \hline & \text { Total Cost per Year } & \text { Total Benefit per Year } \\\hline \text { Plan } A = \text { Levees } & \$ 10,000 & \$ 16,000 \\\hline \text { Plan } B = \text { Small Reservoir } & 24,000 & 36,000 \\\hline \text { Plan C = Medium Reservoir } & 44,000 & 52,000 \\\hline \text { Plan } D = \text { Large Reservoir } & 72,000 & 64,000 \\\hline\end{array}$$ For Plan D marginal costs and marginal bene?ts are

A) $72,000 and $64,000, respectively.
B) $28,000 and $12,000, respectively.
C) $24,000 and $18,000, respectively.
D) $16,000 and $28,000, respectively.