Answer:
Option A 1.0
Step-by-step explanation:
The Extensible Hypertext Markup Language (XHTML) is a Markup language used to create a web page. The XHTML 1.0 is introduced in 2000 as part of the XHTML family. It is a markup language similar to HTML. Its syntax is very similar to HTML 4.01 except the XHTML must follow a strict XML syntax. A web page that follows the XHTML syntax must not contains any invalid markup tag. The adoption of XHTML in web development have improved the consistency of rendering web page among different web browsers. It had been widely used for web development until it was superseded by HTML5.