Refer to the Table Below A)$4
B)$5
C)$9
D)$10

Refer to the table below. The average benefit of 4 units of activity is: $$\begin{array} { | c | c | c | } \hline \begin{array} { c } \text { Units of } \\\text { Activity }\end{array} & \begin{array} { c } \text { Total } \\\text { Cost }\end{array} & \begin{array} { c } \text { Total } \\\text { Benefit }\end{array} \\\hline 0 & \$ 0 & \$ 0 \\\hline 1 & \$ 2 & \$ 12 \\\hline 2 & \$ 6 & \$ 22 \\\hline 3 & \$ 12 & \$ 30 \\\hline 4 & \$ 20 & \$ 36 \\\hline 5 & \$ 30 & \$ 40 \\\hline 6 & \$ 42 & \$ 42 \\\hline 7 & \$ 56 & \$ 43 \\\hline\end{array}$$

A) $4
B) $5
C) $9
D) $10