What Encourages Flooding by Allowing Water to Run Off into Streams

Question

What encourages flooding by allowing water to run off into streams?  
A) Acid rain
B) Deforestation
C) Desertification
D) Bioaccumulation
E) Biological magnification

Accepted Answer

Deforestation removes trees and vegetation that help to absorb and retain water, leading to an increase in surface runoff and ultimately causing flooding.