The section "Polio Mysteries" helps readers understand * 14 points A. How polio can be treated. B. What causes polio. C. How polio affected people in America. D. Why polio is so contagious.

Option C

Explanation:

Polio mystery section deals with the issue of “How polio affected people in America”. It was during the 1951, when there was no medicine for polio and it was affecting the unvaccinated children leading to rise of endemic. Prior to advent of medicine in 1955, it was determined that paediatric injections could had incited polio infection, thereby leading to paralysis.

Hence, option C is correct

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.