Question

Question 7
Which of the following explain why elements such as carbon that make up organic molecules are not permanently removed from the environment?

Pun intended — It's the carbon cycle

a
They are cycled through ecosystems.
b
They are replaced by volcanic eruptions.
c
They are constantly produced from soil nutients.
d
They are replenished by sunlight.

Answer 1

a They are cycled through ecosystems.