The price of good A goes up. As a result, the demand for good B shifts to the left. From this we can infer that:

A) good A is used to produce good B.
B) good B is used to produce good A.
C) goods A and B are substitutes.
D) goods A and B are complements.
E) none of the above

Demand Curve

A graph showing the relationship between the price of a good or service and the quantity demanded.

Complements

Complements are goods or services that are used together, where the use or consumption of one increases the demand for the other, such as coffee and sugar.

Substitutes

Products or services that can replace each other in use, where an increase in the price of one leads to an increase in demand for the other.