Its C Their because their is the only option refering correctly to the sentence. Read the sentence out loud with option C and you will "C" that it is correct lol
The statement, which correctly describes the motion of the buses is this: THE AVERAGE SPEED OF THE BUSES IS EQUAL.
Speed is defined as the distance traveled per unit time; it measures the rate of moving of an object. It is a scalar quantity, that is, it has only magnitude and no specific direction and it is measured in meter per second. A high speed value implies that an object is moving very fast while a low value indicates that the object is moving slowly. For the two buses given in the question, they both moved the same distance in the same amount of time.
