Biological sex is a part of binary. There are still outliers and not everyone is born "biologically male" or "biologically female." I am AFAB, but I am still "biologically" a male because I identify as male. My body does not make me less male and implying that there are only two genders excludes binary people whether you mean to or not. The whole "biology" argument is transphobic because you are labeling someone else's body. I am only saying you need to be more educated on the subject or say "Do you have a male or female character" because again, gender is a spectrum and even if someone is assigned a gender at birth, ""biologically"" speaking they are no less of the gender they identify as because they have certain sex organs. There are males with vaginas, females with penises and everything in between.