The correct answer is indeed 2. The reason behind this is that both statements A and R are individually true, but statement R doesn`t provide a direct explanation for Statement A.

Statement A explains that the weight of a body decreases with the increase of latitude on Earth. This is true because when moving towards the poles, there is a greater distance from the equator to the center of the Earth due to its oblate spheroid shape. This increased distance decreases the force of gravity and hence the weight of an object.

Statement R states that the Earth is not a perfect sphere and this statement is indeed true as Earth is an oblate spheroid—slightly flattened at the poles and bulging at the equator.

However, R does not directly explain A. Even though Earth`s shape contributes to the variation in weight, the primary factor is the varying force of gravity across latitudes, not only the shape of the Earth. Hence, while both statements are true, R does not correctly explain A.