A Profit-Maximizing Monopsonist in a Labour Market Will Continue to Hire

A profit-maximizing monopsonist in a labour market will continue to hire labour until the

A) hourly wage of the labour is equated with its marginal cost.
B) hourly wage of the labour is equated with its average cost.
C) marginal revenue product of labour equals its marginal cost.
D) marginal cost of labour equals its average revenue.
E) marginal product of labour is maximized.