Answer:
I think it's A
must lie btn a clearly defined interval
Answer:
The correct answer is carbon.
Explanation:
Carbon is the major constituent of almost all organic compound.Carbon in form of carbon dioxide is used during photosynthesis in which the CO2 act as reactant that interact with water to generate glucose and oxygen.
On the other hand carbon is found in carbohydrates such as glucose contain 6 carbon atoms,found in protein which contain a carboxy terminal end and an amino terminal end,found in the fatty acid monomers of lipid molecules.
I am not entirely sure, but i think it would be the respiratory system because plants produce oxygen after taking in carbon dioxide, and that is similar to the human respiratory system. I am not completely sure though. hope this helps!