the most appropriate answer is A !! our mind automatically connects everything and thus make a story that we don't even familiar with in actual !!
Explanation:
C is correct.
Newton second law states that force is directly proportional to acceleration with m being the constant of variation.

So


A is wrong, the constant g only happens in free fall or in vertical direction
B and D are wrong due to the mathematical error or equation error
There is no equation here
Atomic Mass Unit is the answer
The ball accelerates because of gravity.