Answer: Option (c) is correct.
Step-by-step explanation:
Correct option: The demand facing the firm is downward-sloping because it is the market demand.
In a monopoly market conditions, there is a single seller in the market and the monopolist firm is price setter. But the demand curve faced by the monopoly firm is downward sloping because monopolist is a single firm who is operating in the market and there is a need to reduce prices if he wants to sell an additional units.