Answer:
A. Fundamental Role
Explanation:
Carbon is present in all the organic compounds, specifically the macromolecules present in the cells of the living beings. The ability of carbon to make four covalent bonds with other atoms and specific orientation of bonded atoms in the space determine the three-dimensional structures of these compounds. And the structure of the compounds regulates their respective functions.
For example, nucleic acids are the polymers of nucleotides which are joined together to make the long chains of DNA and RNA. The stretch of nucleotide sequence of DNA serves as gene and code for specific protein. Likewise, enzymes are proteins and have pockets called active sites to interact with substrates.
