In a cam drive with uniform velocity follower the slope of the displacement must be as shown in Fig. I but in actual practice it is as shown in fig. II (i.e. rounded at the corners)

This is because of
Option (A)
The difficulty in manufacturing cam profile
Option (B)
Loose contact of follower with cam surface
The acceleration in the beginning and retardation at the end of stroke would require to be infinitely high
Uniform velocity motion is a partial parabolic motion
Correct Option:
Question Solution:
In this case, there is infinite acceleration at the beginning and end of the lift. This would create infinite loading force