male and female are sex designators though - so, yet again, if I lived in the UK, as someone of the female sex, but who doesn't have a feminine gender identity (wearing boxers and a bra as we speak - and if it wasn't for my physical characteristics (enormous boobs which get all sweaty if not separated from the skin below) I wouldn't wear a bra at all) - does that make me pan gender or gender fluid?) I would be totally eligible to answer this.
Really, they need to do some decent definitions at the start of this. Surely that's questionnaire writing for beginners? Define your audience?