Answer:
The acceleration of gravity decreases as you move away from the surface of the Earth. The acceleration of gravity at a height of one Earth radius above the surface can be found using the formula:
g' = (R/(R+h))^2 * g
where R is the radius of the Earth, h is the height above the surface, and g is the acceleration due to gravity at the Earth's surface.
If we plug in R = 6,371 km (the radius of the Earth) and h = 6,371 km (one Earth radius above the surface), we get:
g' = ((6,371 km)/(2*6,371 km))^2 * g
g' = (1/2)^2 * g
g' = g/4
Therefore, the answer is D. g/4.