Answer : The correct option is, speed.
Explanation :
Displacement : It is the change in the position of an object that means the distance measuring from starting position to the final position. It is a scalar quantity.
Speed : Speed is defined as the distance traveled by an object with respect to the time taken. It is a scalar quantity that means it tell us about the magnitude of an object not direction.
Velocity : Velocity is defined as the rate of change of position of an object with respect to the time. It is a vector quantity that means it tell us about the magnitude and direction of an object.
The only difference between the speed and the velocity is that the velocity tell us about magnitude and direction but speed tell us about magnitude only.
Direction : It is defined as the position towards which someone or something moves.
From this we conclude that, if we are given the distance and a period of time then we can calculate the speed.
Hence, the correct option is, speed.
