The correct answer is: B. Acceleration
Acceleration is the rate of change of velocity. It is a vector quantity, meaning it has both magnitude and direction. The magnitude of acceleration is the change in velocity divided by the time it takes to change. The direction of acceleration is the same as the direction of the change in velocity.
Velocity is the rate of change of displacement. It is a vector quantity, meaning it has both magnitude and direction. The magnitude of velocity is the distance traveled divided by the time it takes to travel that distance. The direction of velocity is the same as the direction of the motion.
Speed is the magnitude of velocity. It is a scalar quantity, meaning it has only magnitude. The speed of an object is the distance it travels divided by the time it takes to travel that distance.
Therefore, the rate of change of displacement of a body with respect to its surrounding is known as acceleration.