You end up choosing "Anus" off of the list. You still aren't taking this too seriously, and it seemed like a fittingly silly one. To your surprise it now gives you a brief little description of exactly what an anus is, as well as having a section marked "Expected role"... How bizarre. You look over the other options. There is a list for various senses again, all defaulting to checked. There is also another message:
WARNING! DEFAULT SELECTIONS ARE SET TO PERMANENT. PROCEED?
You leave that alone for now. Presumably it can be changed later. Instead you look over the species selection, taking a moment to admire the wide variety. Even several rather exotic creatures! You try to pick a favorite one...