Consider the Following Production and Cost Schedule for a Firm

Consider the following production and cost schedule for a firm.The first column shows the number of units of a variable factor of production employed by the firm. $$\begin{array} { | c | l | l | c | } \hline \begin{array} { c } \text { Total Number of } \\\text { Units of the Factor }\end{array} & \begin{array} { c } \text { Total Number of } \\\text { Units of Output }\end{array} & \begin{array} { l } \text { Price per Unit } \\\text { of Output }\end{array} & \begin{array} { c } \text { Total Cost } \\\text { of Production }\end{array} \\\hline 2 & 12 & \$ 10 & \$ 50 \\\hline 3 & 20 & \$ 9 & \$ 55 \\\hline 4 & 26 & \$ 8 & \$ 60 \\\hline 5 & 30 & \$ 7 & \$ 65 \\\hline 6 & 32 & \$ 6 & \$ 70 \\\hline 7 & 32 & \$ 5 & \$ 75 \\\hline\end{array}$$ TABLE 13- 3
-Refer to Table 13- 3.The marginal product of the 4th unit of the factor of production is

A) 4.
B) 8.
C) 30.
D) 26.
E) 6.