Its called bioamplification
Carbon is the atom, which is necessarily find in the living organism.
All the living organisms are made up of biomolecules. All the biomolecules are organic compounds. The substance cannot be consider as living, if it lacks nucleic acids. There are two types of nucleic acids DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), both have a structure made up of carbon rings and chains.
Other than nucleic acids, proteins, enzymes, hormones etc are also made up of carbon. So, all the living cells, or dead remain of organism must have carbon atom.
Hence, the correct answer is option D. carbon.
The energy needed by a system to initiate a process is called as the activation energy. It describes the minimum energy which must be available to a chemical system with potential reactants to result in a chemical reaction. Hope this answers the question.
Chloroplast has evolved from photosynthetic bacteria