Read the following statements and choose the correct option : Assertion (A) :…

An Assertion-Reason item tests two separate things: whether each statement is factually true on its own, and — only if both are true — whether the reason is the actual physical cause of the assertion's outcome, not merely an unrelated true fact stated alongside it. For matter, the kinetic theory explains compressibility through the amount of empty space between particles: the more spacing a state of matter has, the more room external pressure has to reduce it.

Gas particles are spread far apart, with large intermolecular gaps compared to solids and liquids, so Assertion (A) — that gas can be compressed easily under pressure — is true. Reason (R) explains this correctly: applying pressure forces the particles closer together, shrinking that intermolecular space, and this reduction in spacing is itself the physical act of compression. So the mechanism described in (R) is exactly what produces the outcome stated in (A), making (R) the correct explanation of (A).

• Solids: particles packed with negligible intermolecular space — essentially incompressible.

• Liquids: particles closely spaced with some gaps — compress only slightly, and only under very high pressure.

• Gases: particles widely separated with large gaps — compress readily even at ordinary pressures.

This state-wise contrast confirms both the truth of (A) and (R) and the causal link between them: both (A) and (R) are true, and (R) is the correct explanation of (A).