Concept:The Kreb's cycle is a stage of aerobic respiration that occurs in the mitochondria.
Explanation:The mitochondria have an inner fluid-filled space called the mitochondrial matrix.
The enzymes needed for the Kreb's cycle are present in this matrix.
During the cycle, acetyl-CoA is oxidised to release
CO2,
NADH,
FADH2, and
ATP.
These products are then used by the electron transport chain, which is also located in the mitochondria.
The cycle does not take place in the cytoplasm, nucleus, or ribosomes.
Therefore, the mitochondria is the correct site of the Kreb's cycle.
Answer:A. mitochondria