A curve on a distance-time graph indicate acceleration "an increasing distance is traveled during each unit of time".
Option: D
Explanation:
A distance-time curve represents the distance covered when an entity travels along a straight line. Here the line gradient is proportional to the object's velocity as bigger the gradient (and the steeper the line) quicker the object moves.
It must also be remembered that an entity traveling at a constant velocity while continually changing direction is also accelerating. Velocity, a quantity of vectors, varies when either the magnitude or the direction changes. As dealing with circular motion, this is essential.
