Answer : correct option is (c) velocity.
Explanation :
When an object is moving with a constant speed in a circular path, it is said to be moving in circular motion.
Speed is defined as distance travelled per unit time. In circular motion object moves with constant speed but it keep on changing its direction i.e. its velocity is constantly changing.
Also in circular motion, the object moves tangentially.
Hence, the velocity of object is constantly changing.
