Choose the answer that best represents the situation described below.
Karen is driving across the country. The longer she drives after filling her gas
tank, the more gas she will have to put in next time she fills up.
A. The amount of time that Karen has driven since she last put gas in
her car is a function of how much gas her car needs.
B. The amount of gas Karen has to put in her tank is a function of
how large her gas tank is.
C. The amount of gas Karen has to put in her tank is a function of
how long she has driven since she last put gas in.