How Can You Scientifically Determine Sex?

In our state of west virginia, there was this horrific piece of legislation passed to ban transgenter athletes from playng sports in high school and college. To put it in perspective, that's about the same percentage of the population that has green eyes. And we don't consider either of those things so rare that you'll never see them or know anybody with them in your life. So these, you we do have our own biases against them,. If i may be so bold, and maybe that's can allre evaluate to.