Answer: Option (b) is the correct answer.
Explanation:
The process in which sediment moves downhill is known as mass movement.
Different types of mass movement are landslides, mud slides, slump, creep etc.
Mud flow contains mass of saturated rock particles of all sizes. Mud flow arises due to sudden flood of water or due to heavy rain in a dry region (semi-arid region). Soil and rocks from a large slope area flow along with the flood water and gets washed to a gulch or canyon.
As a result, debris and water moves down canyon and lay out on the gentle slopes below.
Thus, we can conclude that mud flow is most likely facilitates mass movement after heavy rains in a dry region.
