The Main Difference Between a Monopsonist and a Competitive Buyer

The main difference between a monopsonist and a competitive buyer of labor is that

A) the competitor can hire as many workers as it wants at the going wage while a monopsonist can force wages down when hiring additional workers.
B) the competitor can hire as many workers as it wants at the going wage while a monopsonist must raise wages to hire additional workers.
C) the competitor is a small firm while the monopsonist is a large firm.
D) the competitor is also a competitor in product markets while the monopsonist is also a monopoly in product markets.