Answer:
The correct answer is option c.
Explanation:
Pure monopoly refers to a market where there is a single producer selling a product with no close substitutes. Such type of market is very rare.
There is restriction on entry and exit of firms in the market. The firm operating in this market is a price maker and faces a downward-sloping demand curve.
No close substitutes, single seller and barriers to entry are essential conditions for a pure monopoly to exist.