Refer to the Following:
the Amount of Total Output Produced

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 labor is fixed at three units, how much does the second unit of capital add to total output?

A) 100
B) 150
C) 210
D) 360
E) none of the above