Answer: fall; rise
Explanation:
A natural monopoly is a form of monopoly that has a high cost, huge capital base and also a strong economies of scale.
If the government decides to regulate a natural monopoly by forcing them to produce at a point where the natural monopoly's demand curve intersects average cost.
This will lead to a fall in price and there will be a rise in quantity when compared to the natural monopoly if it were allowed to operate unregulated."
