Which organelle fuel the cell with energy to do its activities: A. Nucleus
B. vacuoles
C. Mitochondria
D. Cell membrane

C. Mitochondria

Explanation:

Mitochondria are main sites of aerobic respiration. They are miniature biochemical factories where food stuffs or respiratory substrates are completely oxidised to carbon dioxide and water. The energy liberated in the process is stored in the form of ATP. These bring about the oxidation of carbohydrates, proteins and β-oxidation of fats.The energy (ATP) produced in the mitochondria helps to perform various energy-requiring processes of the cell like muscle contraction, nerve impulse conduction etc. Because of the formation of ATP, mitochondria are called power house of the cell.