Circular motion is the movement of an object along a circular path. In this type of motion, the object continuously changes its direction while maintaining a constant speed. The correct answer to the question is option 'B' - the direction of motion changes continuously. Let's understand why this is the correct answer in detail.

Direction of Motion
In circular motion, the object moves around a center point in a circular path. As it moves, the direction of the object constantly changes. At any given point on the circular path, the object is moving tangentially to that point. This means that the object is moving perpendicular to the radius of the circle at that point. Therefore, the direction of motion is not fixed but changes continuously.

Velocity
Velocity is a vector quantity that includes both magnitude (speed) and direction. In circular motion, the object maintains a constant speed as it moves around the circle. However, the direction of motion changes continuously, which means the velocity of the object also changes. Therefore, the velocity is not constant in circular motion.

Acceleration
Acceleration is the rate of change of velocity. In circular motion, even though the speed of the object remains constant, its direction changes continuously. This change in direction indicates a change in velocity. As a result, there is a non-zero acceleration in circular motion. The object is constantly accelerating towards the center of the circle, which is called centripetal acceleration.

Centripetal Force
The centripetal acceleration in circular motion is caused by a force called the centripetal force. This force acts towards the center of the circle, pulling the object inward. It is responsible for keeping the object in its circular path. Without this force, the object would move in a straight line tangent to the circle. The centripetal force is required to constantly change the object's direction of motion, thereby causing the continuous change in direction.

In conclusion, in circular motion, the direction of motion changes continuously, the velocity is not constant, and there is a non-zero acceleration. Therefore, the correct answer is option 'B'.