Answer:
d. a homogeneous; a downward-sloping
Step-by-step explanation:
The monopoly is a market structure where there is a single bidder of a certain good or service, that is, a single company dominates the entire supply market, and there is a homogeneous product or there are no nearby substitutes. When there is a monopoly in a market, there is only one company capable of offering a product or service that does not have close substitutes.
The monopoly faces a negative slope demand curve: depending on the price set buyers will demand more or less.