Very intriguing thought experiment. What interests me most (especially in the context of our other reading this semester) is, which of the four scenarios would be most disturbing, causing that cognitive estrangement Suvin deems necessary to science fiction?
I think the answer is clearly (3) Inhuman Children. Hybrids that cannot be easily categorized upset both our sensibility and the “natural order of things” (which is usually not so natural after all).