The answer is either B or D. Letter A doesn't make sense and letter C isn't right either because you need rainfall to have fertile plains.
Answer:
C. flows briefly after a period of rainfall
Explanation:
A wadi is dry riverbed that only contains water seasonally. It usually found in arid regions.
- Wadi derived from the Arabic word Wad which means valley.
- For most part of the year, a wadi is usually dry.
- During a brief stint of rainfall, the bed blossoms with water.
- The bed is found in a valley in most arid places.
- They can hold rain water for a short time before the bed dries up.
