What can an ecosystem sometimes repair itself ?

An ecosystem can be illustrated as a biological community where the non-living and living constituents associate with each other. The cutting of trees is generally done for the use of wood products, and medicines that are obtained from trees and plants. The forests that got cleared is considered as disturbed. The migration of birds and animals takes place to a different location in search of habitat and food.  

However, the restoration of clear cut forests can be done as the soil is fertile enough to encourage the development of new plants, that is, the colonization of new plants will occur due to the already present precursors like roots, seeds, and partially trees. The birds and animals again immigrate after colonization of the plants and trees. Thus, the ecosystem will repair itself with the assistance of these precursors.  

i think it's c. i'm not sure but i think so.