Answer:
A. The bacteria could no longer regenerate the NAD+ needed for glycolysis, so it would stop producing ATP.
Explanation:
According to the given information in this question, Lactobacillus acidophilus is a bacterium species that uses the lactic acid fermentation when there is no oxygen in its cell i.e. under anaerobic conditions. This means that it converts glucose to lactic acid during this anaerobic respiration process.
However, if the lactic acid fermentation pathway were blocked under an anaerobic condition, this means that it will be no longer be able to perform respiration and hence stop production of ATP. This is because the bacteria will no longer regenerate the NAD+ (electron acceptor) needed for glycolysis, so it would stop producing ATP. Note that, all living organisms, whether aerobic or anaerobic, undergo GLYCOLYSIS, which is the first stage of cellular respiration.
