New Normal University Has Found It Necessary to Institute a Crime-Control

New Normal University has found it necessary to institute a crime-control program on its campus to deal with the high costs of theft and vandalism. The university is now considering several alternative levels of crime
Control. This table shows the expected total annual costs and bene?ts of these alternatives.
$$\begin{array} { | l | c | c | } \hline & \begin{array} { c } \text { Total Costs per } \\\text { Year }\end{array} & \begin{array} { c } \text { Total Benefits per Year (reduction in } \\\text { the costs of crime) }\end{array} \\\hline \text { Level One -1 Security Officer } & \$ 20,000 & \$ 80,000 \\\hline \text { Level Two -1 Security Officer with Guard Dog } & 30,000 & 120,000 \\\hline \text { Level Three -1 Security Officer with Guard Dog and Patrol Car } & 40,000 & 140,000 \\\hline \text { Level Four -2 Security Officers with Guard Dog } & 50,000 & 155,000 \\\hline \text { Level Five -2 Security Officers with Guard Dog and Patrol Car } & 60,000 & 160,000 \\\hline\end{array}$$ The marginal bene?t of crime control for Level Two is

A) $ 90,000.
B) $40,000.
C) $ 60,000.
D) $200,000.