Answer:
The correct answer would be cellular respiration.
Cellular respiration refers to the set of biochemical reactions which help in converting the energy obtained from food into ATP (adenosine triphosphate) that is, the energy currency of the cell.
It takes place in cells of all the organisms including autotrophs and heterotrophs.
It is initiated in the cytoplasm of the cell but completed in the mitochondria in eukaryotic cells.
It includes reactions like glycolysis, Krebs cycle, electron transport chain, and oxidative phosphorylation.