Answer:
Carbon dioxide
Explanation:
In the making of the muffins, there are many ingredients are used including flour, egg, butter, sugar, and flavoring of fruits. There is also a raising agent, the baking powder or baking soda used that reacts with the batter.
This reaction form bubbles of carbon dioxide, trapped in the air spaces during the baking and muffin raises. Carbon dioxide makes muffins light, by lifting the batter as it bakes.
