Which of the following statements is incorrect?
a) as the population rises, the market demand curve shifts to the right.
b) as a greater fraction of the population becomes elderly, the demand for medical services will tend to increase.
c) changes in the composition of the population affect the demand for a product.
d) none of the statements associated with this question are incorrect.

D) none of the statements associated with this question are incorrect.

Explanation:

As the population rises, demand increases and the market demand curve shifts to the right. 

As a greater fraction of the population becomes elderly, the fraction of the population needing medical services increases and the demand for medical services will tend to increase. The demand curve shifts to the right.

Changes in the composition of the population affect the demand for a product. For example, if the fraction of the elderly in a population increases, the demand for medical services also increases.

I hope my answer helps you

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