Final answer:
If Earth were compressed to the Moon's size, gravity on its surface would increase because the mass remains the same and the distance from the center is reduced, leading to a stronger gravitational pull.
Step-by-step explanation:
If Earth were squeezed to the size of the Moon, the correct answer to what would happen to gravity is A) Gravity will increase because the mass of the Earth remains the same. The gravitational force that a body exerts on objects at its surface is proportional to its mass and inversely proportional to the square of the radius. If Earth's radius were to decrease while its mass remains constant, the surface would be closer to its center, and therefore to its mass, causing the gravitational force to increase. Essentially, gravity depends on how much mass is packed into a given space, along with the distance from the center of that mass.