Answer:
The correct answer is A.
Objects in free fall accelerate due to gravity.
Step-by-step explanation:
Momentum can help an object to keep its state of motion at a constant velocity when no external force is applied. It can never accelerate the object.
According to the laws of motion, we know that acceleration is produced in a body only when a Force is applied in the direction of motion of body.
During a free fall, only the force of gravity is acting on an object and that too in the direction of its motion. Hence, the acceleration produced in a free falling object is due to gravity.