Consider the following statements:

• Assertion (A): The annual temperature range of cold deserts is larger than hot deserts.

• Reason (R): Continentality accounts for the extreme range of temperature.

Correct answer:

Assertion (A) is correct: While both hot and cold deserts have high diurnal (daily) temperature ranges, cold deserts (like the Gobi Desert or the Tibetan Plateau) experience much more extreme annual temperature ranges. In these regions, temperatures can swing from $40^\circ\text{C}$ in the summer to $-40^\circ\text{C}$ in the winter. Hot deserts (like the Sahara) stay relatively warm year-round, resulting in a smaller annual gap.
Reason (R) is correct: The primary driver for this extreme range is continentality. Cold deserts are typically located deep within the interior of large continents, far from the moderating influence of the ocean. Land heats up and cools down much faster than water.

Why (R) explains (A)The Reason provides the geographical mechanism for the Assertion. Because cold deserts are situated in "continental" interiors (often in the rain shadow of high mountains), they lack the humidity and maritime air that would otherwise stabilize temperatures. Without the "buffer" of the sea, the land responds violently to seasonal changes in solar radiation, leading to the large annual range mentioned in (A).