A Racecar, Traveling at Constant Speed, Makes One Lap Around

Multiple Choice

A racecar, traveling at constant speed, makes one lap around a circular track of radius r in a time t. Note: The circumference of a circle is given by C=2πr.
-Which one of the following statements concerning this car is true?

A) The displacement of the car does not change with time.
B) The instantaneous velocity of the car is constant.
C) The average speed of the car is the same over any time interval.
D) The average velocity of the car is the same over any time interval.
E) The average speed of the car over any time interval is equal to the magnitude of the average velocity over the same time interval.