Question

Assertion (A): Dough rises when yeast is mixed into it and kept in a warm place. Reason (R): Yeast releases oxygen gas while breaking down sugar.

Meena's mother soaks rice and urad dal, grinds them into a batter and leaves it in a covered vessel overnight. By morning the batter has risen, looks spongy and smells slightly sour. In winter, she keeps the vessel near the warm kitchen stove because otherwise the batter does not rise well. She then steams the batter to make soft idlis.