Answer:
The correct answer is: mitochondria.
Step-by-step explanation:
The Krebs Cycle and the Electron Transport processes are part of a much bigger process with the intent to generate energy for the cell, Cellular Respiration. Cellular Respiration is basically a series of metabolic reactions that produce ATP molecules using glucose as a substrate.
Both the Kreb Cycle and the Electron Transport Chain occur inside the mitochondria. The first two steps of Cellular Respiration, Glycolysis and Pyruvate decarboxylation, happen in the cytosol and the mitochondria, respectively.
Mitochondria are the organelles responsible for ATP synthesis, though they also function as a calcium reservoir, and participate in processes like apoptosis and synthesis of steroids.
Lysosomes are organelles that contain hydrolytic enzymes that break down polymers. Vacuoles (mostly found in plant cells) are vesicles filled with water that also contain materials that can be harmful to the cell. The Cytoplasm is all the material within a cell except for the nucleus.