Second ionization energies are always than first ionization energies because the remaining electrons are attracted strongly as the positive charge on the ion increases. A large jump in ionization energies is always observed after the electrons have been removed.

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.