The law that if two elements can combine to form two different compounds, the masses of the one element that can combine with a fixed amount of the other element will be in a ratio of small whole numbers.

multiple proportions
definite proportions
o conservation of mass
balanced equations

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.