Answer:
The correct answer is - citric acid cycle.
Step-by-step explanation:
In the third condition, fresh NADH molecules are not forming as NAD+ is getting accumulated fresh NADH molecules are continuously released or generated from the citric acid cycle.
There is no NADH production occurs which means there is some problem with citric acid cyle. Other conditions given is also the result of this inhibition occurs in the citric acid cycle that are decrease in proton gradient and ATP depeletion.