A) Nothing, just totally naked
B) What you’re wearing and anything you carry with you (even if you’re not carrying it right now) like a bag
C) What you’re wearing, what you carry with you, and the contents of your home (it will be teleported within a few hundred metres on the surface in an accessible location, but obviously won’t be connected to any services like electricity or water)
A) Probably okay-ish? I was in the scouts and I’m not completely incompetent at being outdoorsy.
B) Overnight bag probably isn’t much help. At least my breath will be minty.
C) Enjoy the new timeline removed, because I am now the 14th century’s most powerful military.