Answer :

Let's discuss the various factors that influence the acceleration due to gravity:

1. Height:
- The acceleration due to gravity ([tex]\( g \)[/tex]) decreases with an increase in height above the surface of the Earth. This is because gravity is inversely proportional to the square of the distance from the center of the Earth. Mathematically, it is represented as:
[tex]\[ g_h = \frac{g_0 R^2}{(R + h)^2} \][/tex]
where [tex]\( g_h \)[/tex] is the acceleration due to gravity at height [tex]\( h \)[/tex] above the Earth's surface, [tex]\( g_0 \)[/tex] is the acceleration due to gravity on the surface, and [tex]\( R \)[/tex] is the radius of the Earth.

2. Depth:
- The acceleration due to gravity decreases as one goes below the Earth's surface. This is due to the reduction in the effective mass that exerts gravitational force. Inside the Earth, the value of [tex]\( g \)[/tex] is given by:
[tex]\[ g_d = g_0 \left(1 - \frac{d}{R}\right) \][/tex]
where [tex]\( g_d \)[/tex] is the gravity at depth [tex]\( d \)[/tex].

3. Shape of the Planet:
- The Earth is not a perfect sphere but an oblate spheroid, meaning it is slightly flattened at the poles and bulging at the equator. The acceleration due to gravity is slightly greater at the poles (where the Earth is flat) compared to the equator (where the Earth bulges). This variation is due to the variation in the radius and also due to the rotation of the Earth.

Given that acceleration due to gravity varies with height, depth, and shape of the planet, the correct answer is:

d) all of these