You are missing that the plain and obvious question should be "Sex? (M/F)"
That it is not is the direct fault of some very stupid activists thinking we can all have our own personal definition of Man and Woman based on whatever bundle of stupid sexist ideas we happen to have and persuading companies and publuc bodies and health providers that they need to treat these individual personal self images as if they are actually meaningful, as if they are more relevant than actual sex.
And so the language has been debased and corrupted to the point this medical form literally has no way request information they actually need, "What is your sex?", and know it has been clearly understood and accurately answered.
Instead, they have to ask what sex your were "assigned" at birth, something that in reality never actually happened, and expect everyone to know they are supposed to pretend they were "assigned" a sex that they actually always were and always would have been even if no one had been present at their birth to "assign" (or in real language, notice the fact of) anything at all.
It's offensive, it's assinine, it's extremely damaging to women's rights in particular and I am utterly sick of pandering to it.
Go back to simple, sex based language, stop paying lip service to stupidity like "assigned at birth", and if someone wants to define themselves by sexist stereoypes to the degree they put their own healthcare at risk because they don't like admitting the language of sex applies to them too, that's their choice and we should respect that and let them live with the consequences instead of driving everyone round the houses in the genderist language clown car just to save a handful of people from the consequences of their own rejection of reality.