The Capital Stock Is Fixed at 50 Units,the Price of Capital

Multiple Choice

The capital stock is fixed at 50 units,the price of capital is $30 per unit,and the price of labor is $25 per unit. $$\begin{array} { c c } \text { Output } & \begin{array} { c } \text { Average } \\\text { Variable Cost }\end{array} \\\hline 10 & \$ 40 \\20 & 30 \\30 & 45 \\40 & 60\end{array}$$ Given the above,how much does the 23rd unit of output add to the firm's total cost?

A) $75
B) $135
C) $750
D) $1,350
E) none of the above