HTML5的正确doctype是?

HTML5的正确doctype是?
A.＜!DOCTYPEhtml＞(正确答案)
B.＜!DOCTYPEHTML5＞
C.＜!DOCTYPEHTMLPUBLIC"-//W3C//DTDHTML5.0//EN"
D."http://www.w3.org/TR/html5/strict.dtd"＞