Proper Capitalization for the Sahara Desert

What is the correct capitalization for the proper noun in the given sentence?

Although the Sahara Desert is generally flat, the snow-capped mount Tahat rises above the swirling sands of the desert.

Answer:

The correct answer is A. Although the Sahara Desert is generally flat, the snow-capped Mount Tahat rises above the swirling sands of the desert.

Option A contains the correct capitalization for the proper nouns. Proper nouns are names used for places or people and are spelled with an initial capital letter. In this sentence, "Sahara Desert" and "Mount Tahat" are proper nouns as they are the names of unique places.