What Does the Law of Demand Assume Will Occur If

What does the law of demand assume will occur if the price of a good increases?  

A)  that people will recognize that the good's price may be even higher in the future, so they buy now rather than later 
B)  that consumers tend to shift their purchases to relatively cheaper substitutes 
C)  that people will buy less of the good in the hope that it will be cheaper in the future 
D)  that the consumer's money income increases, and he or she is less able to buy all goods including the good whose price has increased