How do plate tectonics affect mountains? Mountains outline plate tectonic boundaries.
Plate tectonics spreading can create mountains.
Plate tectonic collisions can create mountains.
Mountains provide evidence for plate tectonics.

C. Plate tectonic collisions can create mountains.

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.