Final answer:
Ethanol is an example of a reduced organic compound that may be produced during fermentation, with this process being particularly familiar in the contexts of alcoholic beverage production and leavening of bread.
Step-by-step explanation:
An example of a reduced organic compound that may be produced during fermentation is ethanol (B). During alcohol fermentation specifically the enzyme-catalyzed conversion of acetaldehyde to ethanol occurs. This reduction uses NADH as the electron donor, resulting in the formation of ethanol.
This process can be observed in the fermentation of pyruvic acid by yeast commonly used in the production of alcoholic beverages and bread rising due to CO₂ gas evolution.