Read this passage.

as readers explore this book, i hope they will gain an appreciation for modern dance. i assert that hip-hop deserves the same recognition as ballet, tap, and jazz, and this book supports that assertion. through an explanation of history, choreography, and famous performances, i will prove hip-hop’s worth.

what feature distinguishes this passage as an introduction?

it provides a high-interest “hook.”
it clearly explains the book’s topic.
it adds credibility to the author.
it is written by an expert on the subject