A Firm's Production Function Is Given By $Q = K L$

Multiple Choice

A firm's production function is given by $Q = K L$ . The marginal products of labor and capital are, respectively, $M P _ { L } = K$ and $M P _ { K } = L$ . The wage rate of labor is $w = \$ 10$ and the rental rate of capital is $r = \$ 20$ . The firm wants to produce 1,800 units of output in the most efficient way possible. How much does the firm spend?

A) $2,000
B) $1,300
C) $1,200
D) $1,100