Answer:
B. Speed is how fast an object is moving: speed = distance/time.
Velocity is the rate at which an object changes position: velocity = displacement/time
Step-by-step explanation:
Distance is a scalar quantity. It has only magnitude. So, distance/time is also scalar. If you are travelling at 100 km/h, that is your speed, because you could be going in any direction.
Displacement is a vector quantity. It has both magnitude and direction So, displacement/time is also a vector. If you are travelling east at 100 km/h, that is your velocity, because you are stating both your speed and the direction