Argument 1: A zygote isn’t a human being.
Me response: That opinion goes against the opinions of 95% of biologists.
Argument 2: A zygote is a human being, but bodily autonomy outweighs the right to life.
My response: If that’s what you believe, then you would have to be fine with a conjoined twin killing their twin in the name of bodily autonomy. They are connected, so if bodily autonomy outweighs the right to life, then you would have to support one conjoined twin’s right to kill their twin. I have met people that defended that view and I think most normal people don’t. But if it’s not acceptable to kill your conjoined twin in the name of bodily autonomy, what makes abortion any different?
Argument 3: A kid set up for adoption gets messed up so badly it’s worse than death.
Response: The vast majority of foster kids get adopted within 5 years and the foster system makes sure the parents are competent and not child rapists or abusers.