Final answer:
The Rub' al-Khali, known as the empty quarter, is the correct answer (d) and is recognized for its harsh conditions, uninhabited areas, and significant oil deposits.
Step-by-step explanation:
The Rub' al-Khali is also known as the "empty quarter" because of its harsh sand dunes and uninhabited areas. The correct answer is d. Rub' al-Khali.
The Rub' al-Khali, or Empty Quarter, is the largest contiguous sand desert in the world, located in the southern part of the Arabian Peninsula. Encompassing most of the southern third of the Arabian Peninsula, including parts of Saudi Arabia, Oman, the United Arab Emirates, and Yemen, it is a vast stretch of desert that covers approximately 250,000 square miles. This region is known for its harsh environment and extreme temperatures, as well as its significant oil resources. Due to the scarce water resources, there is very little human habitation, making agricultural activity highly dependent on alternatives such as underground aquifers, oases, or desalination of seawater. This highlights the vital importance of water as a natural resource in such an arid region.