Give an example of chemical equilibrium you have come across into your day-to-day life. Explain how it meets the definition of equilibrium.

the atomic mass is the bottom number on the element.

-steel jelly

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.