All of them could be intentional/unpreventable, we are only talking about an injury so I would say the plane crash.
Merlin/ NF2 tumor suppressor functions through impacting mechanisms related to proliferation, apoptosis, motility, adhesion, and invasion.
It depends on the type of drug you mean, such as medicinal drugs like marijuana, or bad drugs like cocaine or heroine. But the best answer(in my opinion) is B.