Why do authors vary sentence structure in their writing?

A. To make their writing fictional.

B. To make their writing simpler.

C. To make their writing biographical.

D. To make their writing more interesting.

D. To make their writing more interesting.

Authors vary sentence structure to create rhythm and flow in their writing, to emphasize certain points, to keep the reader engaged, and to add variety and creativity to their work. By using a combination of short and long sentences, simple and complex structures, authors can effectively convey different moods, feelings, and ideas in their writing.