Is dough rising: chemical or physical

rise, as a result of fermentation (an irreversible chemical change). Yeast transforms the sugar in the dough into carbonic gas (carbon dioxide) and alcohol (ethanol). The trapped carbon dioxide makes the dough rise, and the alcohol produced by fermentation evaporates during the baking process.

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.