Columns 1 and 2 Make Up a Portion of a Monopolist's

Multiple Choice

Columns 1 and 2 make up a portion of a monopolist's production function for a single variable input,labor.Columns 2 and 3 represent the demand function facing the monopolist over this range of output: $\begin{array}{c}\begin{array}{c}(1) \\\text {Units of Labor}\\3 \\4 \\5 \\6 \\7\end{array}\begin{array}{c}(2) \\\text {Units of Output}\\370 \\490 \\570 \\600\\620\end{array}\begin{array}{c}(3) \\\text {Price}\\\$10\\9\\8\\7\\6\end{array}\end{array}$
How much does the fifth unit of labor add to the firm's total revenue?

A) $1.875
B) $80
C) $150
D) $4,560
E) none of the above