A:
Content Model Declaration

Content Rule

(#PCDATA|tt|i|b|u|s|strike|big|small|em|strong|dfn|code|samp|kbd|
 var|cite|abbr|acronym|a|img|applet|object|font|basefont|br|
 script|map|q|sub|sup|span|bdo|iframe|input|select|textarea|label|
 button)*

Exclusions

(a)