The correct answer is C. Mitochondria.
Mitochondria are organelles found in eukaryotic cells that are responsible for energy production. They are often called the “powerhouses of the cell” because they produce adenosine triphosphate (ATP), the cell’s main energy source.
Cytoplasm is the jelly-like substance that fills the cell and contains all of the cell’s organelles except for the nucleus. Ribosomes are organelles that are responsible for protein synthesis.
Option A is incorrect because the cytoplasm is not the site of cellular respiration. Option B is incorrect because ribosomes are not the site of cellular respiration. Option D is incorrect because cellular respiration does take place in an organelle.