Antigens) and therefore fail to protect against it." (Paragraph 14) How does paragraph 3 contribute to the development of ideas in the text?
A. It emphasizes the positive impact that vaccines have had on people's overall
health.
B. It shows how potentially dangerous some diseases can be to people.
C. It reveals that not everyone takes vaccines to protect against these diseases.
D. It stresses how some diseases continue to persist despite vaccines.