What Kind of Underwear Does Batman Wear?

I was reading this article on Buzzfeed about ridiculous questions that people have asked on Yahoo Answers about underwear. The last question was this:

Tis an interesting answer, and I wonder if it could be found anywhere in the canon? Any comic geeks out there know the answer, or can perhaps propose a better one?

But why stop at Batman. What does Superman wear? Does the Flash go commando? I reckon the Green Lantern wears briefs. I wonder if Wonder Woman wears a wonder bra?

[Yahoo Answers]