How does yeast make wheat dough rise before it goes into the oven?

Answer: Yeast feeds on sugar and releases gas bubbles that puff the dough.

Baking soda reacts with acid and releases gas that puffs the dough. — Wrong. Baking soda does react with acid to release gas, so this describes a real leavening method. But yeast bread rises because the yeast itself ferments sugars and produces carbon dioxide; it is not the acid-base reaction of chemical leavening.

Trapped air in the dough heats up and expands to puff the loaf. — Heating trapped gas helps bread expand in the oven, but it does not explain rising before baking. Yeast produces carbon dioxide during fermentation, and the dough traps that gas. Early baking can add further rise before the structure sets.

Yeast feeds on sugar and releases gas bubbles that puff the dough. ✓ — Correct! Yeast is a single-celled fungus that feeds on sugars in the dough. Its fermentation releases carbon dioxide, and that gas gets trapped in the gluten network, so the dough expands. Baking sets the bubbles in place.