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,if the firm produces 30 units of output,how many units of labor does the firm use?

A) 30
B) 45
C) 54
D) 60
E) none of the above