Natural regeneration of forests and woodlands is the process by which new trees grow from seeds that have fallen and germinate where they have fallen. The biggest problem with natural regeneration is that is unpredictable. As a result, it cannot be used for commercial farming. For most of the last two or three hundred years, forests and woodlands have restocked by using transplants grown in nurseries. The young trees are planted in equidistant rows. This allows each tree the best possible change of optimal growth.
The germinal layers that give rise to the digestive system is Ectoderm, Endoderm, Mesoderm, Respectively. And the best answer among your choices is the last option which is C. I hope you are satisfied with my answer and feel free to ask for more