Consider the Following Production and Cost Schedule for a Firm

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

A) $28.00.
B) $7.50.
C) $- 11.00.
D) $3.67.
E) $2.00.