Answer:
the law of demand.
Step-by-step explanation:
Under the law of demand, the demand for a particular good is given by the amount of good that buyers wish to acquire in a given period of time. In this case, the demanded quantity of a product varies inversely with its price, because when the price of the product goes up the demand quantity of that product goes down, similarly when the price of the product goes down, the demanded quantity of that product goes up.