Answer- All the needs of animals living in a forest are fulfilled. It is because-
They get fresh oxygen as plants consume carbon dioxide and give out oxygen to the animals for respiration.
Plant eating animals (herbivores) have plenty of food available as forests contain a large number of plants.
These herbivores flourish in forests, which in turn, also provides food for the carnivores.
Trees provide shelter to many forest animals like monkeys, snakes, birds, etc