No clear answer to this. I'm sure some guys would say A and some would say B. Pretty is a little stronger than cute in terms of looks, but cute implies a nice personality, which 'pretty' may or may not have.
So really I think most guys couldn't give you a clear cut answer. Great question though!
My exboyfriend used to say it went [Unattractive, Not Bad, Acceptable, Pretty, Cute, Beautiful, Gorgeous] for normal looks and [Hot, Sexy, Beautiful] For sexual attraction :P Of course that's only his way xD