At critical speed

A.The shaforuns smoothly
B.The shaft runs with noise due to vibrations
C.The shaft becomes dynamically unstable with negligible lateral amplitudes
D.The shaft becomes dynamically unstable with large lateral amplitudes
E.None of the above

A cam profile is the

A.Profile of path traced by a cam follower
B.Actual working contour of the cam
C.The profile of the path to be traced by the mechanism driven by follower
D.Total surface area of the cam
E.Path which the cam follower traces