Answer:
Gravitational force
Explanation:
Gravitational force is what is making the feather go down. It's pushing the feather down, without the Gravitational force, the feather would have been going up, and not down. Just like us. Gravitational force is what keeps us humans from floating ( unless ur an alien jklol), So yeah Gravitational force is the force that acts upon the feather to fall towards the ground at a constant speed.
Btw, u never listed the forces here just ....
Hope this helped!
