The arid expanse covering north africa is called

The arid expanse covering the northern part of Africa is called the 'Sahara Desert'.

Explanation:

The total area of the Sahara desert is 92,00,00 sq. kilometers. It stretches east-west across the entire northern part of Africa and consumes about 25% area of the continent. It houses 10 African countries and forms a natural physio graphic boundary between the world to the north and the rest of the African continent.Out of all the hot deserts in the world, the Sahara desert is the largest and the driest.

The answer to this question is  c. pharmaceutical accumulation  reclaimed water refers to the water that being used again after it already  used for agricultural purposes.this type of water often contains pharmaceutical accumulation because of the chemical fertilizer that is used for the plants is absorbed into the water.