If you do not wish to designate your gender and prefer to deactivate your account due to being forced to make this choice then you may do so if you choose.
Okay, deviantART. If you would prefer that I -- a transgendered person -- delete my account rather than stay, participate, and increase your ad revenue, I can do that. Sure, no problem.
I won't be updating this account any longer, except to announce where I will be moving my art to once I find a place.
But personally, I refuse to stay on a site that thinks erasing me, and others like me, is an acceptable behavior.
More information is available here if you'd like to better u