Answer the Question on the Basis of the Following Output

Answer the question on the basis of the following output data for a firm.Assume that the amounts of all nonlabor resources are fixed. $$\begin{array}{l}\begin{array} { c c c } \text { Number of}&&\text{ Units of }\\\text { Workers } & & \text { Output } \\\hline0 & & 0 \\1 & & 40 \\2 & & 90 \\3 & & 126 \\4 & & 150 \\5 & & 165 \\6 & & 180\end{array}\end{array}$$ Refer to the data.Average product is at a maximum when:

A) five workers are hired.
B) four workers are hired.
C) three workers are hired.
D) two workers are hired.