In a Competitive Market, a Firm's Supply Curve Dictates the Amount

In a competitive market, a firm's supply curve dictates the amount it will supply. In a monopoly market the

A) same is true.
B) supply curve conceptually makes sense, but in practice is never used.
C) supply curve will have limited predictive capacity.
D) decision about how much to supply is impossible to separate from the demand curve it faces.