Explanation:
Simple harmonic motion requires a restoring force.
Simple harmonic motion should be periodic.
Option A:
When a rubber band is stretched,the internal forces of the rubber band pulls the band inside.So,internal forces are the restoring forces in a rubber band.
The motion is periodic as well since the the rubber band makes to an fro motion expanding ans contracting.
So,this performs SHM.
Option B:
There is no restoring force and no periodicity.
So,this is not SHM.
Option C:
There is no restoring force and no periodicity.
So,this is not SHM.
Option D:
There is periodicity but no restoring force.
So,this is not SHM.