When Developing a Demand Schedule, Nonprice Factors Such as Buyer

When developing a demand schedule, nonprice factors such as buyer taste are held constant because:

A) these factors rarely change.
B) these factors have no effect on buyers' attitudes toward products.
C) there is not enough information about any of these factors to work with them.
D) a demand schedule focuses on how a product's price influences the amount buyers would purchase.