Answer:
B. Photosynthesis
Step-by-step explanation:
Oxygen is necessary for the survival of most living species on Earth. But the atmosphere of the planet does not always contain this essential substance for life, and one of the greatest mysteries for science is to know how and when the photosynthesis of oxygen initially began, the process responsible for the production of oxygen from the rupture of water molecules on our planet. Now, a team led by geobiologists from the California Institute of Technology (Caltech) has found evidence of a precursor process in which manganese is involved, which acts as a predator of cyanobacteria, the first group of organisms that use photosynthesis to release oxygen in the environment.
Photosynthesis is the process by which the energy that comes from the Sun is used by plants and other organisms to break down water and carbon dioxide molecules to make carbohydrates and oxygen. Manganese is required for water breakdown to occur, so when scientists began to wonder what evolutionary steps had led to the presence of an oxygenated atmosphere on Earth, they began by paying attention to the evidence of the photosynthetic oxidation process of manganese in cyanobacteria, which was earlier in time. Since oxidation is simply a process that involves the transfer of electrons to increase the charge of an atom, and since this can be achieved using light or carbon dioxide, it could have occurred before the emergence of oxygen on our planet.