The answer should be letter B I'm sorry if not
The answer is 'The Biosphere.'
The heart is a vital organ, and its functioning is essential to life.
All your other organs may fail, and you will still be alive. Even if your brain stops working, and your heart is healthy, you will be alive in the vegetative state where you won't be conscious at all. However, once your heart stops working, you die, which means it is the most important organ in your body.
since they all eat different things:
deer, sheep cattle eat plants,
wolves eat meat and insects eat plants or other insects the answer would be
Consumers, as they all obtain food from plants or animals
