When is comparison of (15200) km and (7516.6) km suitable for understanding India's size?

Correct answer: When both are compared as length figures

The direct answer is A: both figures should be treated as length measurements. The unit km means kilometre, a unit used for distance or length. India’s north–south extent is about 3,214 km and its east–west extent is about 2,933 km, while 15,200 km is commonly used for the length of land boundary and 7,516.6 km for the coastline including island territories. Even if the figures describe different kinds of length, they can be compared as lengths when the purpose is to understand size. Option A works because both quantities have the same physical unit, kilometre. Option B is wrong because area is measured in square kilometres and percentage has no kilometre unit; these are different types of measurement. Option C is wrong because ranks are numbers showing position, not distances, and would not be measured in km. Option D is wrong because population is counted in persons, not kilometres. Always identify both the unit and what the number measures before comparing. Memory cue: same unit and same kind of quantity make a comparison meaningful.