Which of the following is not true for a profit maximizing single-price monopolist in the long run?

By subsidizing the provision of public education, the government

A) generates an increase in the quantity of educational services demanded. B) pushes the per-unit price that consumers pay for educational services below the market clearing price. C) pushes the per-unit price that producers of educational services receive above the market clearing price. D) all of the above.

You explain to your friend Haslina, who runs a catering service called "Meals in a Zip," about an economic theory which asserts that consumers will purchase less of a product at higher prices than they will at lower prices. She contends that the theory

is incorrect because over the past two years she has raised the price of her catered meals and yet has seen a brisk increase in sales. How would you respond to Haslina? A) Haslina is right; she has evidence to back her claim. The theory must be erroneous. B) I will explain to her that she is making the error of reverse causality: it is the increase in demand that has enabled her to raise her prices. C) I will explain to her that there are some omitted variables that have contributed to an increase in her sales such as changes in income. D) Haslina is making the mistake of assuming that correlation implies causation.