In world geography, which one of the following deserts is the largest hot desert by area among the options given?

Introduction / Context:
This question checks basic world geography, specifically knowledge of major deserts of the world. Many competitive exams test whether candidates can distinguish between different deserts by type and size. The Sahara Desert is widely known as the largest hot desert on Earth, while Antarctica and the Arctic are larger cold deserts. The question restricts attention to the deserts listed in the options, so we focus on comparing these four names and identifying which covers the greatest area as a hot desert region.

Given Data / Assumptions:

• Four deserts are listed as options: Thar, Sahara, Kalahari and Arabian.
• The question asks for the largest of all deserts among the options provided.
• The focus is on general size in terms of area, not temperature details or population.
• No numerical areas are given, so the answer must come from basic factual recall.

Concept / Approach:
In standard geography references, deserts are often classified by climate into hot and cold deserts and compared by area. When students learn about world physical geography, they usually memorise major records such as highest mountain, longest river and largest desert. Among the hot deserts, the Sahara in northern Africa is consistently described as the largest, with an area of several million square kilometres. The Thar Desert is significant but limited mainly to parts of India and Pakistan. The Kalahari and Arabian deserts are also large but still smaller in area than the Sahara. Recognising this basic ranking leads directly to the correct choice.

Step-by-Step Solution:
Step 1: Recall that the Sahara Desert is located in northern Africa and extends across many countries. Step 2: Remember that the Thar Desert is mainly confined to northwestern India and adjoining Pakistan, and is much smaller than the Sahara. Step 3: Note that the Kalahari Desert lies in southern Africa and is also smaller than the Sahara in total area. Step 4: Recognise that the Arabian Desert covers parts of the Arabian Peninsula but still does not match the huge expanse of the Sahara. Step 5: Conclude that among the four options, the Sahara Desert is the largest hot desert by area.

Verification / Alternative check:
As a quick verification technique, try to remember a standard list of superlatives: highest mountain Everest, longest river Nile and largest hot desert Sahara. Many geography textbooks and exam guides present these together. If learners can recall that trio, it becomes easy to confirm that Sahara must be the correct option. Another check is to visualise a world map and notice that the Sahara covers a major portion of northern Africa, which is much more extensive than the regional deserts in the other options.

Why Other Options Are Wrong:
Thar Desert is the largest desert in India but is a regional desert and far smaller than the Sahara in area. Kalahari Desert in southern Africa is a semi arid region, but its total area is less than that of the Sahara. Arabian Desert on the Arabian Peninsula is large but still significantly smaller than the Sahara Desert.

Common Pitfalls:
A typical error is to confuse the phrase largest desert with largest cold desert and think of Antarctica, which is not listed here. Another issue is over focusing on deserts familiar from national context, such as the Thar Desert for Indian students, and incorrectly assuming that the local desert is the largest. To avoid such mistakes, it is useful to memorise a small table of world geography records and revise it regularly so that these standard facts remain firmly in memory.

Final Answer:
Among the deserts listed in the options, the Sahara Desert is the largest hot desert by area.