Labor Economists Sometimes Refer to Labor Demand as "Derived" Demand

Multiple Choice

Labor economists sometimes refer to labor demand as "derived" demand. In this context, where does "derived" come from?

A) The firm's production function.
B) The union's willingness to accept a lower wage.
C) Consumer demand for the firm's product.
D) The firm's profit.
E) The degree of competition in the firm's industry.