part a\nearths gravitational field is strongest at \nview available hint(s)\nhint 1.\nhow is gravitational…

Brief Explanations:

The gravitational field strength (g) is given by (g=\frac{GM}{r^{2}}), where (G) is the gravitational - constant, (M) is the mass of the Earth, and (r) is the distance from the center of the Earth. At the Earth's center, the net gravitational force from all parts of the Earth on a test mass is zero due to symmetry. As we move from the center to the surface, the gravitational field strength increases. At infinity, the gravitational field strength (g) approaches zero according to the inverse - square law. At the Earth's surface, the gravitational field strength is the strongest among the given options.

Answer:

D. Earth's surface