The Table Below Describes the Relationship Between the Number of Workers

The table below describes the relationship between the number of workers hired by a call center each hour and the number of calls the call center can make each hour. The call center has only 1 telephone. The telephone costs the firm $5/hour (regardless of how many calls are made) , and each worker is paid $10 per hour. $$\begin{array} { | c | c | c | } \hline \begin{array} { c } \text { Calls Per } \\\text { Hour }\end{array} & \begin{array} { c } \text { Number of } \\\text { Telephones } \\\text { Per Hour }\end{array} & \begin{array} { c } \text { Number of } \\\text { Workers } \\\text { Per Hour }\end{array} \\\hline 1 & 1 & 2 \\\hline 2 & 1 & 4 \\\hline 6 & 1 & 6 \\\hline 16 & 1 & 8 \\\hline 22 & 1 & 10 \\\hline 24 & 1 & 12 \\\hline\end{array}$$ If the price of a telephone increases to from $5 to $10 an hour and nothing else changes, then:

A) total cost would not change.
B) marginal cost would increase by $5 at every level of output.
C) marginal cost would not change.
D) average total cost would increase by $5 at every level of output.