(i) She should use comments in HTML.Any text to make comments in HTML, should be preceded by <! and should end with ->Example:<body><!-This is only used for comment->Welcome</body>(ii)HTML is used to display data and to focus on formatting of data, whereas XML is used to describe data and focus on what data is.HTML tags are not case sensitive whereas XML tags are case sensitive.HTML tags are predefined, whereas XML tags are not predefined.XML is used to store and transfer the data over different platforms while HTML is used to design webpages.