A rigid body not fixed in some way can have either pure translation or a combination of translation and rotation.
In rotation about a fixed axis, every particle of the rigid body moves in a circle which lies in a plane perpendicular to the axis and has its centre on the axis.
A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false
D. If both assertion and reason are false.