Which of the following best describes the XHTML 1.0 transitional and its requirements?

The XHTML 1.0 Recommendation describes three variations or "flavors." Which of the following best describes the XHTML 1.0 transitional and its requirements?

A.
Developers must use Cascading Style Sheets (CSS) for all formatting.

B.
Developers can use any markup tags that we supported in HTML Recommendations 1.0 or later.

C.
Developers can use either Cascading Style Sheet (CSS) or HTML 4.0-compilant markup tags for all formatting.

D.
Developers must use Cascading Style Sheets (CSS) for all formatting and use frames with XHTML 1.0-compliant markup tags.