Assertion (A): 60°–65° latitudes in both the hemispheres have a low-pressure belt instead of high pressure. Reason (R): The low-pressure areas are permanent over oceans rather than on land.

Answer: (b) Both A and R are individually true but R is not the correct explanation of A

The sub-polar low is caused dynamically (rising air where westerlies meet polar easterlies); R is true but not the reason.

The idea

A dynamic low forms when air converges and rises because of circulation, rather than local surface heating alone. Near the subpolar belt, warmer westerly air meets colder polar easterlies along fronts. The tendency for oceanic lows to persist describes where they occur. It does not explain the lifting that produces low pressure.

Westerlies meet polar easterlies → Air converges along the polar front → Lighter warm air is lifted → Air rises and diverges aloft → A belt of relatively low surface pressure develops

Why the others are wrong

(a) R doesn’t explain A.

(c) The key treats R as true.

(d) A is true.

The trap

R is a real feature (Aleutian and Icelandic lows) but not the cause.

Also know

The Icelandic Low lies in the North Atlantic and the Aleutian Low in the North Pacific. They are climatological centres, strongest in winter, not individual storms permanently parked in one place. Equatorial lows are largely thermal; subtropical highs are largely dynamic. Continental seasonal heating can interrupt the ideal pressure-belt diagram.