Option 3rd. anaerobic process that breaks down glucose
Explanation:
On observing only glycolysis it is an anaerobic process. As none of the nine steps of glycolysis involve the use of oxygen.
After, immediate finish of glycolysis, the cell continues respiration either in anaerobic or anaerobic direction this depends upon the presence of oxygen and mitochondria.
If oxygen and mitochondria is present the glycolysis will be broken down to produce 2 molecule of pyruvate as the end product which will be utilized in further processes(in kreb's cycle and ETS).
In case if oxygen is absent then different types of alcohols and and acids are formed.
Result: Glycolysis does not involve oxygen and hence is a anaerobic process.
