Refer to the Following:
the Amount of Total Output Produced

Multiple Choice

Refer to the following:
The amount of total output produced from various combinations of labor and capital.

$\begin{array}{cccc} &\text { Units of Capital }\\&& 1 & 2 & 3&4 \\\hline &1 & 50&120&160&180 \\\text {Units }&2 & 110&260&360&390 \\\text {of }&3 & 150&360&510&560\\\text {Labor }&4 & 170&430&630&690 \\&5 & 160&4801&710&790 \\\end{array}$
-If the capital stock is fixed at one unit, diminishing returns begin with the

A) first unit of labor.
B) second unit of labor.
C) third unit of labor.
D) fourth unit of labor.
E) fifth unit of labor.