It's so cold in the D, how the FUCK are we 'pose to keep any kind of peace around here?

I wasn't going to post this, but i've just been singing it all day so i've got to. I mean singing it in my head of course, not bellowing it out loud in public, or people would think i was a dick. But someone please tell me what the fuck is ''The D''? Sorry for being ign'ant.