In Constructing the Demand Graph to Show How the Price

In constructing the demand graph to show how the price of a good price affects how much of it the buyers will buy, the convention that economists follow is to measure price on the

A) horizontal axis because it is the independent variable.
B) vertical axis because it is the dependent variable.
C) vertical axis even though it is the independent variable.
D) horizontal axis even though it is the dependent variable.