Answer: The correct answer would be option C.
Step-by-step explanation:
Mitochondrion, also known as energy house of the cell, is a cell organelle mainly involved in the production of cellular energy, that is, ATP.
It is a double membrane-bound cell organelle which contains majority of enzymes involved in cellular respiration including ATP synthase.
All the metabolic processes involved in cellular respiration apart from glycolysis take place in mitochondria only. For example, Krebs cycle, oxidative phosphorylation, electron transport chain, chemiosmosis, et cetera.
Thus, if a cell contains numerous mitochondria then, the main function of the cell would be energy production.