I don't want a trans girl as a sales rep
Why not?
The girl is a man mentally, which is disgusting.
There is no reason to discriminate against her. If she can do the job, she should be hired.
It's my right. I can choose to hire who I think is right for the job.
That is true, but you should not reject her because she is trans. That is discrimination. As long as she can do the job, she should be hired.