Sam Buys Gasoline and Coffee Each Week

Sam buys gasoline and coffee each week. In order to draw his budget line between gasoline and coffee, Sam would have to know

A) only how much income he has available to spend on gasoline and coffee.
B) only the prices of one gallon of gasoline and one pound of coffee.
C) only how much gasoline he wants to buy and how much coffee he wants to drink.
D) both how much income he has to spend and the prices of one gallon of gasoline and one pound of coffee.