Final answer:
The correct answer is B, where the center of gravity would be higher than the center of mass due to the variation in the strength of gravity at different distances from Earth, influencing the weight and consequently the center of gravity but not the center of mass.
Step-by-step explanation:
The correct response to the question about two equal masses at different distances from Earth's surface in a non-uniform gravitational field would be B. The center of gravity would be higher than the center of mass because the farther mass weighs more. This is due to the fact that in a non-uniform gravitational field, the strength of gravity (and thus the weight of an object) varies with distance from the Earth's surface. The center of gravity is the point where the gravitational forces on a body can be considered to act. Because the farther mass experiences less gravitational pull, the center of gravity will be shifted towards it relative to the center of mass, which depends only on the spatial distribution of mass and is not influenced by the strength of the gravitational field.
It's essential to understand that while the center of mass is purely a function of the distribution of mass in a system, the center of gravity shifts with changes in the local strength of gravity. The center of mass remains constant as it is the weighted average of the positions of the masses in the system. When the gravitational field is uniform, such as close to the Earth's surface where gravity is approximately 9.8 m/s², the center of gravity coincides with the center of mass. However, in a non-uniform gravitational field, they do not coincide.