Answer the following question given this paragraph: 

In alcoholic fermentation, glycolysis is followed by a step that produces alcohol and carbon dioxide. This step also forms additional molecules of ATP. It occurs in yeast, such as the yeast in bread. Carbon dioxide from alcoholic fermentation creates gas bubbles in bread dough. The bubbles leave little holes in the bread after it bakes. You can see them in the bread in Figure below . The holes make the bread light and fluffy.


Q: Bubbles in bread dough are created by what gas produced during alcoholic fermentation?


A:
carbon dioxide