Which fact is most basic for understanding India's size and extent?

Correct answer: India’s area, latitudinal-longitudinal extent and coastline

The governing concept is geographical extent: it is described through area, boundaries, latitude, longitude, and coastline. India’s area gives an overall measure of its size, while latitudinal and longitudinal limits show how far it spreads north–south and east–west. The coastline further explains the country’s maritime extent and physical relationship with surrounding seas. Thus option A contains the essential group of facts. River names, mountain heights, and city populations may be important in other geography topics, but each alone cannot define the total size and extent of a country. The word “only” makes options B, C, and D especially incomplete. A complete geographical description combines measurements, coordinates, boundaries, and coastal limits.