Which of the following is the largest hot desert of the world?

Deserts are broadly classified as hot deserts, formed under subtropical high-pressure belts (for example the Sahara, Kalahari, and Thar), or cold deserts, found at high latitudes or high altitudes (for example Antarctica and the Gobi). Within the hot-desert category specifically, deserts are ranked and compared purely by total surface area.

• Sahara Desert (North Africa): approximately 9.2 million square kilometres.

• Kalahari Desert (Southern Africa): approximately 900,000 square kilometres.

• Thar Desert (India-Pakistan border): approximately 200,000 square kilometres.

• Atacama Desert (South America): approximately 105,000 square kilometres; it is famous instead for being the driest non-polar desert, not the largest.

The Sahara's area is roughly ten times that of the Kalahari and far exceeds the combined area of the Thar and Atacama, making it the largest hot desert among the given options.

Cross-checking against cold deserts: Antarctica (about 14 million square kilometres) and the Arctic (about 13.9 million square kilometres) are larger overall, but the question specifically asks for the largest HOT desert. This distinction rules out the polar deserts and confirms the Sahara as the correct answer among the offered options.