下列样式定义字体间距为0.5倍间距、水平左对齐、垂直顶端对齐、有下划线正确的定义是:()
A. p{text-decoration:underline; letter-spacing: 0.5em; vertical-align: top; text-align: left;}
B. p{text-decoration:0.5em; letter-spacing: underline; vertical-align: top; text-align: left;}
C. p{text-decoration: left; letter-spacing: top; vertical-align: 0.5em; text-align: underline;}
D. p{text-decoration:underline; letter-spacing: 0.5em; vertical-align: left; text-align: top;}