The correct answer is:
CO2
Yeasts use sugars in the same way that we do. They transform the sugar into carbon dioxide gas in the fermentation method. If you brew wine or beer at home, you wait until the fermenter stops bubbling .
Explanation:
During the production of bread, yeast cells utilize the sugar and starts growing. Alcoholic fermentation takes place, during which ethanol and carbon dioxide are formed. Alcohol evaporates, and carbon dioxide provide the bread its fluffy structure.
Ethanol fermentation causes bread dough to rise. Yeast people utilize sugars in the dough and create ethanol and carbon dioxide as waste products. The carbon dioxide forms droplets in the dough, extending it to a foam. Less than 2% ethanol persists after baking.