Which practice can result in increased soil erosion?
a. shelterwood harvest
b. clear-cutting
c. thinning
d. crop rotation

b. clear-cutting

Explanation:

The clear-cutting is a practice that results in increased soil erosion. The clear cutting is a practice of removal of trees and other vegetation from a region. This will lead to soil erosion because of the fact that the roots of the trees and other vegetation helps in binding the soil. After clear cutting the soil becomes loose and it is affected by water, wind and other physical agents, which takes away the soil and transport it to other locations.  The soil looses it's fertility due to erosion.    

we would need to see the picture to answer it

c. heat from the poles back down towards the equator.