下列哪个CSS样式中设置了左浮动？
选项：

A:* { margin: 0px; padding: 0px; list-style: none; font-size: 13px;};
B:#header h1 { float: left;};
C:a { color: #555; text-decoration: none;};
D:#header h1 a { background: url(image/logo.jpg); width: 476px; height: 102px; display: block; text-indent: -9999px;}