Answer:
Correct answer is often formed on the dry side of mountain ranges.
Explanation:
First option is not correct as sand is covering only 20 percent of deserts, while plants can survive in desert even for a large period of time without water.
Second option is also not correct. Deserts can be found everywhere. In Asia, Africa, Australia...
Third option is correct. Mountains are blocking rainy weather, that would allow the growth of plants.
Last option is not correct. We can find deserts in cool areas.
