I'm thinking the brain. The brain produces hormones and chemicals that tell the body to grow. And you also need to think a lot when trying to survive, which is when the brain comes in handy.
It is A. The Sum of all the actual feeding relationships in an ecosystem.
Asteroids are rocky bodies orbiting the sun. Asteroids are irregular is shape and size. The size varies from few feet to 500 miles across. Majority of the asteroids lie in asteroid belt which lies between the orbits of Mars and Jupiter.