Which are mostly anaerobic?
A. Algae
B. Mosses
C. Fungi
D. All the above

Hint: Fermentation is the anaerobic process. Glucose anaerobically forms ethanol and carbon dioxide.

Complete Answer:
1) Fungi are heterotrophic organisms. They depend on autotrophs for their nutrition. Some species of fungi are one of those organisms that can grow in anaerobic respiration i.e. in absence of oxygen such example is Neocallimastigomycota which are toxic to oxygen.
2) Facultative anaerobe is an organism that can grow in presence of oxygen but can also grow in absence of oxygen by switching to fermentation.
3) Most soil-borne fungi are examples of facultative anaerobes; Fusarium oxysporum, Penicillium abeanum, Neurospora crassa, and Trichophyton rubrum are of ammonia fermentative.

Therefore, the correct answer is option C. Fungi.

Additional information: Fermentation is the process of making ATP from sugar (glucose) which is in absence of oxygen. Such organisms use aerobic respiration It involves glycolysis, but not the other two stages of aerobic respiration. Fungi such as yeasts perform fermentation. These organisms are utilized in making yogurt, bread, wine, and biofuels.

Note: The organisms that do not require oxygen as they have usually had a fermentative metabolism, but they are not harmed by the presence of oxygen as obligate anaerobes are aerotolerant anaerobes.