Which of the following would NOT cause a shift in the demand curve?

A change in the price of the item does not cause a shift in the demand curve; instead, it results in a movement along the demand curve itself. The demand curve illustrates the relationship between the price of a good and the quantity demanded at those prices.

When the price of a product changes, consumers will respond by adjusting the quantity they are willing to purchase, but this does not change the overall demand for the product itself. The demand curve remains in the same position; therefore, the quantity demanded will either increase or decrease depending on whether the price drops or rises.

In contrast, factors such as a change in consumer income, consumer preferences, or population size affect consumers' willingness and ability to buy the product at all price levels, thereby shifting the entire demand curve to the left or right. Recognizing these distinctions is crucial for understanding how different factors impact market dynamics.