A: No. While trauma triggers vary (and can include foods, smells, and locations), and it is in principle possible that somebody, somewhere, might be triggered by the presence of a trans woman, there is no general association between trans women and rape trauma. (Contrast rape jokes, which are generally triggering to victims and should be avoided.) Why would you presume that kind of connection between trans women and rape?
Most of the time, people have no way of knowing whether those around them are cis or trans; someone who can’t reliably recognize trans women can’t reliably be triggered by their transness.
Panicking about trans women isn’t an effective way to support survivors of sexual assault (regardless of those survivors’ trans status). A better idea would bet to support RAINN by volunteering, donating, or fundraising. Survivors, perpetrators, and bystanders come in all genders, but if you are specifically a man looking to support women, this thread has a bunch of helpful suggestions.
A Trans 101 Blog 