Explanation:

All the given options correctly describe differences between HTML and XHTML:

MIME Type

• HTML uses text/html as its MIME type.
• XHTML uses application/xml+xhtml or application/xhtml+xml for better XML parsing.

Case Sensitivity

• In HTML, tag and attribute names are case-insensitive (e.g., <div> is the same as <DIV>).
• In XHTML, they must be lowercase (e.g., <div> is valid, but <DIV> is not).

Special Characters Handling

• In XHTML, special characters like <, >, and & must be written as character entities (&lt;, &gt;, &amp;).
• In HTML, browsers are more forgiving about unescaped special characters.

Since all the given options correctly highlight actual differences, the correct choice is (D) None of the mentioned.