A Government Agency Is Having Problems with Personal Telephone Calls

A government agency is having problems with personal telephone calls made during working hours. Because each minute of a personal call costs the agency $0.50 in wasted wages, it has decided to hire operators to monitor calls. The agency wants to hire the number of operators that will minimize the total cost of personal calls.

$\begin{array}{cc}\begin{array}{c}\text { Number of } \\\text { operators }\end{array} & \begin{array}{c}\text { Minutes of personal } \\\text { calls(per week) }\end{array} \\\hline 0 & 3900 \\1 & 2300 \\2 & 1300 \\3 & 600 \\4 & 100 \\5 & 0\end{array}$
-What is the most the agency would be willing to pay the fifth operator?

A) $100
B) $200
C) $400
D) $500
E) none of the above