Answer: D. pricing
The pattern of demand can be altered by pricing. That is, when the prices of similar products from different competitors change, it will most likely affect the demand for your product. The demand curve is often drawn with the idea that the prices of similar products are not affected.
Therefore, when other similar products have a price change, the demand curve will be significantly altered. It will either go upward or downward — depending on the trend. For example, if the price of a similar product rises, the demand for that product will increase, and if the price falls, the demand will also decrease. Other factors that may affect the demand for a product are income, customer preferences, consumer population, etc.