The correct answer is B:Change in price.
Explanation:
To explain in detail, let's first understand the concept of demand. Demand refers to the quantity of a good or service that consumers are willing and able to purchase at a given price level. A shift in demand refers to a change in the entire demand curve, which represents a change in the quantity demanded at all price levels.

Now, let's discuss the factors that cause a shift in demand:

1. Change in income: An increase in consumers' income generally leads to an increase in demand for goods and services, as people can afford to buy more. Conversely, a decrease in income leads to a decrease in demand.

2. Change in price: This factor does not cause a shift in demand. Instead, it causes a movement along the demand curve. When the price of a good or service increases, the quantity demanded decreases, and when the price decreases, the quantity demanded increases. This is known as the law of demand. A change in price does not shift the demand curve but causes a movement from one point to another on the same demand curve.

3. Change in fashion: As consumer preferences and tastes change, the demand for goods and services may also change. For example, if a particular clothing style becomes popular, the demand for that style will increase, causing a shift in the demand curve.

4. Change in prices of substitutes: Substitutes are goods that can replace each other in consumption. If the price of a substitute good increases, consumers may choose to buy the original good instead, which will increase the demand for the original good. On the other hand, if the price of a substitute decreases, consumers may switch to the substitute, causing a decrease in demand for the original good. This results in a shift in the demand curve.

In conclusion, changes in income, fashion, and prices of substitutes can cause shifts in demand, while a change in price results in a movement along the demand curve rather than a shift.