Refer to the Accompanying Table Below A)1
B)3
C)4
D)6

Multiple Choice

Refer to the accompanying table below. According to the Cost-Benefit Principle, how many units of this activity should be carried out? $$\begin{array} { | c | r r | r | } \hline \text { Units of Activity } & { \text { Tatal Cast } } & { \text { Tatal Benefit } } \\\hline 0 & \$ 0 & \$ 0 \\\hline 1 & \$ 30 & \$ 100 \\\hline 2 & \$ 40 & \$ 160 \\\hline 3 & \$ 60 & \$ 190 \\\hline 4 & \$ 100 & \$ 210 \\\hline 5 & \$150 & \$ 220 \\\hline 6 &\$210& \$ 225 \\\hline\end{array}$$  

A) 1
B) 3
C) 4
D) 6