Skillful writers use informative headings and subheadings to

A) conceal the basic structure of the document.
B) guide readers to think a certain way about the topics covered.
C) add a decorative flair to mundane documents.
D) take up space so the document doesn't look too short.

Informative headings and subheadings are used to guide readers and provide an organizational structure for the document. They help readers understand the topics covered and make it easier to navigate the document. Skillful writers use these headings to guide readers to think about the topics covered in a certain way, based on the language and tone used in the headings.