When experts first predicted major weather-related coffee crop failures in Central and South America in 1986, the price of coffee already on grocery shelves in the United States increased sharply. When coffee became temporarily more scarce, the usefulness to society of "coffee conservation" increased. The immediate sharp price increase (which soon leveled off) gave consumers an incentive to
a. buy all the coffee they could at the higher prices and hoard it, since there was obviously a shortage.
b. drink as much coffee as possible at the higher price.
c. start conserving coffee immediately and switch to other beverages if it was easy to do so.
d. ignore the price of coffee and drink it as they normally would.

At the substantial increase in the price of coffee, consumers will be able to store the available coffee and ration it properly and as a substitute good, people change drinks because the price increases and the other drinks are at the same or lower price, generating that the when the coffee returns to its normal price, people drink it normally again