Which mistake is common in facts related to India's area?

Correct answer: Writing only kilometre instead of square kilometre

The governing concept is the dimensional correctness of a measurement. Area represents a two-dimensional surface and therefore requires a square unit, such as square kilometres. Writing only “kilometre” changes the meaning to a length, so option A identifies the common mistake. Option B describes correct practice, not an error. Option C concerns a ranking and does not identify a unit mistake in the area value. Option D may refer to India’s approximate share of the world’s area in some textbook contexts, but it is a percentage statement rather than the specific unit error asked about here. The safest check is to ask whether the quantity is area; if it is, the unit must include “square.”