Carbon dioxide is the answer
They would at least get 50% of energy from hay to make the milk or more
Answer:
The answer is the sun.
Explanation:
Level a represents the producers which you can tell, by their name, that they make their food. Producers are mainly comprised of the plants of our world. They get their energy from the sun and through photosynthesis, they turn it into energy.
By the way, B would be primary consumers which are the herbivores, C are the secondary consumers which include us people, and D are the decomposers, which include worms.
