One of the most commonly used fermented cereal amongst these is

The correct option is Bread.

Fermentation is a metabolic process wherein microorganisms, such as yeast or bacteria, convert carbohydrates (sugars and starches) into alcohols or organic acids. This process is extensively utilized in food production to enhance flavor, texture, and preservation.
Among the options provided, wheat and rice are raw cereal grains rather than fermented products, whereas yoghurt is a fermented dairy product rather than a fermented cereal.
Bread is a classic, widely consumed food product prepared by baking a dough made from cereals (primarily wheat flour) that has been fermented using yeast (such as Saccharomyces cerevisiae). The yeast ferments the sugars present in the dough, producing carbon dioxide gas and ethanol, which causes the dough to rise and gives bread its characteristic light and airy texture. Therefore, bread is one of the most commonly used fermented cereal products.