Which of the following best describes a substitute good?

A substitute good is defined as a product or service that can be used in place of another. This means that when the price of one good rises, consumers are likely to switch to the alternative good, leading to an increase in the demand for that substitute. For example, if the price of tea rises, consumers might choose to buy coffee instead, as both serve similar purposes as beverages.

The other choices describe different economic concepts. A complementary good refers to a product that is typically consumed together with another good, like printers and ink. A good that has no impact on demand does not fit the definition of a substitute, as it suggests a lack of relationship with demand shifts. Lastly, a good with negative elasticity would indicate that as the price rises, the quantity demanded also decreases, which is not a characteristic of substitute goods. Therefore, the choice that correctly defines a substitute good is the one that states it can be used instead of another good.