Which ingredient can produce gas during baking to help dough rise?

• A. Yeast
• B. Baking Soda
• C. Air
• D. Sugar

Answer: (C)

Leavening comes from gas expanding inside dough as it bakes. The air that's mixed into or trapped in the dough forms tiny pockets. When the dough heats up, that air expands and the moisture also turns to steam, helping the dough rise. So the gas that actually provides the lift can come from the air already present in the mixture, making air a leavening source in this context.

Yeast and baking soda do create gas through fermentation or chemical reactions, but they generate new gas rather than relying on air that's already there. Sugar itself doesn't produce gas on its own; it mainly affects flavor, browning, or feeds other processes.