The correct option is B centrifugal force
An object placed on a rotating platform is a case of non-inertial frame of reference. To describe its motion using Newton's Laws we need to add fictitious forces in the system. In the frame of reference of the object, a fictitious force, centrifugal force acts on the object which acts in the outwards radial direction. Therefore, the object placed on a rotating platform move away from the centre due to centrifugal force.