Table 73 -Refer to Table 7

Multiple Choice

Table 7.3
$$\begin{array} { c c } \begin{array} { c } \text { Number } \\\text { of Workers }\end{array} & \begin{array} { c } \text { Total } \\\text { Output }\end{array} \\\hline 0 & 0 \\1 & 10 \\2 & 40 \\3 & 100 \\4 & 140 \\5 & 160 \\6 & 170 \\7 & 150\end{array}$$
-Refer to Table 7.3,which the number of workers and total output produced in a firm.The marginal product of the third worker is _____

A) 20.
B) 100/3.
C) 60.
D) 50.
E) 140.