How Is the Marginal Product of Labour Defined

Multiple Choice

How is the marginal product of labour defined?

A) As the change in total revenue that results when an additional unit of a labour is hired.
B) As the additional labour required to produce one more unit of output.
C) As the additional labour cost of producing one more unit of output.
D) As the change in output that a firm produces as a result of hiring one more worker.