Given the Total Product Schedule Below, for Which Unit of Labor

Multiple Choice

Given the total product schedule below, for which unit of labor is the marginal product of labor the highest?
$$\begin{array} { | l | l | l | l | l | l | l | l | } \hline \text { Units of Labor } & 0 & 1 & 2 & 3 & 4 & 5 & 6 \\\hline \text { Total Product } & 0 & 2 & 5 & 9 & 14 & 21 & 25 \\\hline\end{array}$$

A) 2nd
B) 3rd
C) 4th
D) 5th