a) periodic motion

b) simple harmonic motion

c) periodic but not simple harmonic motion

d) non-periodic motion

Answer:

The correct answers are

a) periodic motion

c) periodic but not simple harmonic motion

Explanation:

The earth rotates on its own axis in a circular motion that takes a regular length of time to complete one complete revolution. So it periodic.
However, motion does not revolve around a fixed point from which we can calculate its displacement or around which it moves on both sides, therefore it is not simple harmonic motion.