What is a prologue? Why might a author include a prologue in their story? What information should the reader learn in a prologue?

Now we have "lords of dogtown," a fiction film based on the very same material and indeed written by peralta. not only is there no need for this movie, but its weaknesses underline the strength of the doc.” based on this passage, we can conclude that the author a. prefers documentaries to fictional stories c. likes the movie “lords of dogtown” very much b. prefers the documentary over “lords of dogtown” d. feels that it took too long to make the movie “lords of dogtown”