what are the purposes of a prologue in a play?
to provide information about the inner thoughts and feelings of a character
to set the mood and tone of the play and provide background information
to provide information about how the stage should be set and what props are needed
to give some insight into the relationships among different characters
to provide a hint to the audience about what will happen later in the play

what excerpt?

explanation:

the purpose of the heading in the passage is to identify who is telling the story.

this excerpt is part of the book sugar changed the world (2010) written by marc aronson and marina budhos. as the book has been written by two people, the heading "marc" indicates that this specific excerpt is being narrated by aronson. in the fragment, marc describes his grandfather's story after hearing it from his cousin. however, there are other excerpts where budhos is the one that tells the story of her family.

aronson and budhos, who are husband and wife in real life, decided to write sugar changed the world when they found out how sugar, which had an important role in slavery and economy, changed their ancestors' lives.