Final answer:
Acceleration due to gravity impacts the force on an object by increasing it; since force equals mass times acceleration (F = ma), as the acceleration due to gravity (g) increases, so does the force or weight of the object (W = mg).
Step-by-step explanation:
The impact of acceleration due to gravity on the force on an object is that it increases the force on the object. According to Newton's second law of motion, force is equal to mass times acceleration (F = ma). In this context, the acceleration a is replaced by g, the acceleration due to gravity, which is approximately 9.80 m/s² on Earth's surface. Thus, the force on an object due to gravity, also known as weight (W), is W = mg. When the acceleration due to gravity increases, the force on the object increases proportionally provided the mass remains constant.
Therefore, in response to the student's question, the correct answer is: a. The force on an object increases with gravity.