Answer:
He can ask which set will have the least mass and most acceleration.
Explanation:
Because F = m x a is true and we have the highest acceleration between the sets which means we do have the highest force and because gravity is playing a big role in that process we could say the objects force is mass divided by gravity times the acceleration equals the force unless if there was 0 gravity we would have the original formula. In conclusion, he should ask the question of which set will have the least mass and most acceleration.