According to the Geo-scientists, the shape of the earth is: 1. round 2

According to the Geo-scientists, the shape of the earth is:
1. round
2. spherical
3. close to that of a sphere
4. an oblate ellipsoid
Select the correct answer using the code given below:

2, 3 and 4
1, 2 and 3
1 and 2 only
3 and 4 only
This question was previously asked in
UPSC NDA-2 – 2015
The correct answer is D) 3 and 4 only. According to geoscientists, the Earth’s shape is most accurately described as an oblate ellipsoid (or oblate spheroid), meaning it is flattened at the poles and bulges at the equator due to its rotation. While it is also approximately spherical or close to that of a sphere, “oblate ellipsoid” is the precise geodetic term for its overall shape. “Close to that of a sphere” is also accurate as it acknowledges the deviation from a perfect sphere while still capturing the general shape. “Round” and “spherical” are less precise terms used in common language.
Geoscientists use precise terms like ‘oblate ellipsoid’ to describe the Earth’s shape, which deviates from a perfect sphere.
The Earth’s equatorial diameter is about 43 km larger than its polar diameter. This slight bulge makes ‘oblate ellipsoid’ the most accurate geometric model. Saying it’s “close to that of a sphere” is also factually correct, as the deviation is relatively small compared to the overall size. Therefore, options 3 and 4 represent the descriptions used by geoscientists, with 4 being the most specific geometrical model.