Answer:
A dimer (/ˈdaɪmər/) (di-, "two" + -mer, "parts") is an oligomer consisting of two monomers joined by bonds that can be either strong or weak, covalent or intermolecular. The term homodimer is used when the two molecules are identical (e.g. A–A) and heterodimer when they are not (e.g. A–B).
Explanation:
A, because plants consume carbon dioxide and produce oxygen
A. An organism that is genetically identical to the organism from which it was produced
