Normal force. Normal force is always present when there is contact between two items. Normal force is counteracting the gravitational force.
Explaining the incorrect answers:
-It’s not frictional force because friction only occurs when something is moving and also making contact. While there is contact in this scenario, the apple is not moving.
-There is no applied force; that would be something like a push.
-There is a gravitational force on the table, but it doesn’t keep the apple’s push in check. They are both pointed downwards, to the earth.
Hope this helps!
