Answer:
The correct answer is option d.
Explanation:
A monopoly is a market structure where there is a single firm in the market with no close substitutes. The firm is a price maker. There is high barriers to entry in the market.
Similar to monopoly other imperfect competition such as monopolistic competition and oligopoly also have barriers to entry, and are price makers. But the firms in such markets have different demand curve than the market demand curve.
But in a monopoly there is only single firm, so the market demand curve is the same as individual firm's demand curve.
