Hey there! :D
Force is energy or strength that as the characteristic of movement or physical action.
A push or pull is a force. It moves something physically. If I was going to push a door for it to open, I would physically be moving it.
Inertia is a common tendency to remain unchanged or do nothing. If you are not doing anything, you are not applying force or movement to anything. This would not be the correct answer. We can eliminate "C" and "E"
Since a push and pull both are a force, then "D" is the answer. They both are.
I hope this helps!
~kaikers