You are creating a Web site for a customer. You will use an external linked style sheet for
controlling the style of elements and giving a consistent look and feel to the site. Which of the
following best describes this external style sheet?

A.
A text file that uses the .css file name extension and contains style definitions and HTML
formatting tags

B.
A text file that uses the .htm file name extension and contains only style definitions

C.
A text file that uses the .htm file name extension and contains style definitions and HTML
formatting tags

D.
A text file that uses the .css file name extension and contains only style definitions