Yes, all of the 4 choice is really possible. And what come out from my mind first is AI. Yes, as the first 3 choice is possible, but at least human know what is it and "may" try not to make it or avoid to let it happen. But for AI, we have no idea what will it be, but we are trying to develop it.
I read a news today, which is about developer teaching AI to bargain with each other. And you know what? The AI they develop a language to help for the bargains themselves. That's what we can't predicted.
RE: Top 4 Ways Humans Might Go Extinct