Describe the relationship between the direction of the velocity vector and the direction of the acceleration for a body moving in a circle at constant speed

Uniform circular motion can be described as the motion of an object in a circle at a constant  speed. As an object moves in a circle, it is constantly changing its direction.

At all instances, the object is moving tangent to the circle. Since the direction of the velocity vector  is the same as the direction of the object's motion, the velocity vector is directed tangent to the  circle as well.

An object moving in a circle is accelerating. Accelerating objects are objects which are changing  their velocity - either the speed (i.e., magnitude of the velocity vector) or the direction. An object  undergoing uniform circular motion is moving with a constant speed. Nonetheless, it is accelerating  due to its change in direction. The direction of the acceleration is inwards.

answer; (d) spontaneous processes are characterized by the overall conversion of order to disorder;