Which of the following does not represent a proportional relationship?
A. Zoe earns a base salary of $500 plus 3% commission
B. Dane drove 200 miles at a consistent speed for four hours
C. Water leaks from the faucet at a rate of 1/2 of a liter per hour
D. A recipe for biscuits calls for 3 cups of flour and 1 1/2 teaspoons of baking soda
