Answer:
The correct answer is option D.
Step-by-step explanation:
A monopoly market consists of the only a single firm which produces goods with no close substitutes. Such a firm is a price maker and faces a downward-sloping demand curve.
There is no supply curve as the behavior of producers cannot be predicted. A producer can charge any price but it is able to maximize profits at the point where the price is equal to marginal cost.
Thus the change in quantity due to an increase in the demand for monopoly products cannot be predicted.