(c) : Mitochondrion is the organelle which bears various enzymes participating in Krebs' cycle. Each mitochondrion is covered by double membrane. The inner membrane is selectively permeable and forms foldings called cristae. The inner membrane bears oxysomes, enzymes of fatty acids, succinate dehydrogenase (of Krebs' cycle) and electron transport system. All other enzymes of Krebs' cycle are present in the mitochondrial matrix.