Suppose a Production Function for a Firm Takes the Following

Suppose a production function for a firm takes the following algebraic form: Q = (0.5) KL - 40L,where Q is the output of paintbrushes per week.Now suppose the firm is operating with 100 units of capital (K = 100) and 30 000 units of labour (L = 30 000) .What is the output of paintbrushes per week?

A) 30 000
B) 300 000
C) 1 200 000
D) 1 500 000
E) 3 000 000