(Figure: Mileage and Speed by Car Weight) Which Statement About

Multiple Choice

(Figure: Mileage and Speed by Car Weight) Which statement about the graph is CORRECT? I. The heavier the vehicles, ceteris paribus, the lower the mileage. II. The higher the speed of the vehicle past 50 miles per hour, ceteris paribus, the lower the mileage.
III) Weight and speed have a linear relationship with mileage.

A) I only
B) II only
C) I and II
D) I, II, and III