There are many correct answers to this question. The first correct answer is A, the increasing population. With the rising population, it becomes more difficult to feed those in the population. The next correct answer is B, Drought. Drought makes it difficult for the land to thrive.
D, Over-grazing of animals, is also correct because allowing the animals to eat down to the roots stops the plants from growing. F, Arid climate, is correct because the climate is necessary for the plants to grow correctly. The last correct answer is G, Deforestation, which is when forests are destructed. When they are destructed, the land is unable to grow