Refer to the Following:
Amount of Total Output Produced from Various

Multiple Choice

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

$\begin{array}{cccc} &\text { Units of Capital }\\&& 1 & 2 & 3 \\\hline &1 & 80 & 100 & 120 \\\text {Units }&2 & 180 & 220 & 260 \\\text {of }&3 & 270 & 330 & 390 \\\text {Labor }&4 & 340 & 420 & 500 \\&5 & 390 & 490 & 590 \\&6 & 410 & 530 & 650\end{array}$
-If capital 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) none of the above