How should the relation between the escarpment-like western edge of the Deccan Plateau and the narrow western coastal plain be understood?

Correct answer: The Western Ghats form a high barrier parallel to the coast.

The Western Ghats form a nearly continuous, high escarpment along the western margin of the Deccan Plateau. They run roughly parallel to the Arabian Sea coast, leaving only a relatively narrow coastal plain between the mountains and the sea. This physical arrangement explains why option A is correct. The Ghats also influence rainfall: moisture-laden southwest monsoon winds rise over them and produce heavy orographic rain on the western side. The Eastern Ghats are a separate, more discontinuous range, while the Aravallis and Meghalaya Plateau do not describe this plateau–coast relationship. The key idea is “Deccan Plateau–Western Ghats–narrow western coastal plain.”