Jane Says That Any Change in Velocity Is Directly Proportional $\Delta$

Multiple Choice

Jane says that any change in velocity is directly proportional to the time interval over which the change took place. Dana says that is true only when the acceleration is constant. Which one, if either, is correct?

A) Dana, because it is true only when the acceleration is constant.
B) Jane, because we can define ax, avg so that $\Delta$ vx = ax, avg $\Delta$ t.
C) Jane, because ax, avg always is equal to .
D) All the other statements are correct.
E) None of the other statements are correct.