Answer:
The correct answer is E.They retain water to prevent flooding and erosion.
Step-by-step explanation:
Rain forests are used to be very dense forests where lots of raining takes place. The forest floor can soak up lots of rain and during flood dense forest with woodland trees do not allow water to run fast through them thereby reducing flood's effect significantly.
The roots of the trees in the forest binds to the soil on the floor and prevent soil erosion during flooding. Study shows that water retention is more in summer than in winters. Forest can store lots of water and transfer it to the streams which is helpful in providing clean water to the people in dry season.
Therefore, the correct answer is E. They retain water to prevent flooding and erosion.