Easy question :) 1 mol is equal to?

6.022 × 10²³

Explanation:

One mole of a substance is equal to 6.022 × 10²³ units of that substance 

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.