The Manager of the Customer Service Department at a Bank

The manager of the customer service department at a bank can hire employees with a high school degree (HS) who earn $10,000 annually or employees with a bachelor's degree (B) who earn $20,000. The manager wants to maximize the number of customers served given a fixed payroll.

$\begin{array}{lll}& \text {Number of Adaitional Customers Served }\\ \text { Worker}& \text {High School Degree }& \text {Bachelor's Degree }\\1 s t & 80 & 90 \\2nd & 60 & 80 \\3 r d & 50 & 60 \\4 t h & 40 & 40 \\5 t h & 35 & 35 \\6 \text { th } & 30 & 25\end{array}$
-If the manager currently has three HS and three B, what must be true?

A) More customers could be served if the manager hires fewer HS and more B.
B) More customers could be served if the manager hires more HS and fewer B.
C) The manager is making the correct decision because the marginal contributions are proportionate.
D) The manager is not making the correct decision because