Intertropical Convergence Zone (ITCZ), a low-pressure zone, is located

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Correct — D, at the equator. The Intertropical Convergence Zone (ITCZ) is the low-pressure belt near the equator where the north-east and south-east trade winds meet and converge. Intense solar heating there lifts warm, moist air, creating an equatorial low ('doldrums') with rising air and heavy convectional rain. Its mean position is over the equator, though it migrates a little north and south with the overhead Sun.

Why the other options are wrong — (a) That transition (around 30° N and S) is the sub-tropical HIGH-pressure belt (horse latitudes), not the equatorial low ITCZ.  (b) The meeting of westerlies and polar easterlies (around 60° N and S) is the sub-polar LOW, a different pressure belt from the ITCZ.  (c) The poles carry cold, dense, descending air — the polar HIGH-pressure zones, the opposite of the equatorial ITCZ.

Concept: Earth has four broad pressure belts arranged by latitude: the equatorial low (ITCZ) at 0°, the sub-tropical highs near 30°, the sub-polar lows near 60°, and the polar highs near 90°. The ITCZ forms because the equator gets the most direct sunlight, so air is heated, expands and rises, lowering surface pressure. Where the two trade-wind systems converge and rise, cloud and rain are abundant.

State PCS 2018 Q33 — Geography PYQ with Answer

State PCS 2018 Q33 — Geography PYQ with Answer