An object will accelerate in free fall because the only force acting on it is gravity. true or false.

The conclusion is true, but I'd reach it in a slightly different way:

-- An object in free fall is acted on by only the force of gravity.

-- Since there's only one force on it, the forces can't be balanced,
and the net force on it can't be zero.

-- Since the net force on an object in free fall can't be zero,
such an object will always accelerate.

Dis your correct answer