$\begin{array}{ll}\hline \mathrm{L} & \mathrm{Q} \\\hline 0 & 0 \\1 & 20 \\2 & 50 \\3 & 90 \\4 & 125 \\5 & 140 \\6 & 150\end{array}$

Multiple Choice

$\begin{array}{ll}\hline \mathrm{L} & \mathrm{Q} \\\hline 0 & 0 \\1 & 20 \\2 & 50 \\3 & 90 \\4 & 125 \\5 & 140 \\6 & 150\end{array}$
-Given the table above, the marginal productivity of the third worker is:

A) 30.
B) 40.
C) 50.
D) 90.