Which of the following is the main problem and solution in the text?

A.
Kenya’s land and people were suffering. Wangari started a tree planting movement that restored health to the people and land.

B.
The people did not have enough fresh food, so they were unhealthy. When the people began to get food from the trees and plants they had planted, they started to get their health back.

C.
Though they still had to cut down some trees, they made up for it by planting two new trees every time they did so.

D.
Wangari and the people who did what she said still struggled; water was not easy to get, so they dug it out of deep holes.