Which statement best describes active immunity?

Which statement best describes active immunity?

• A. Stimulates antibody production
• B. Appears following exposure to an antigen
• C. Is a direct result of an immune response
• D. All of the above

Answer: (D)

Active immunity is when the body's own immune system mounts a response to a specific antigen, creating targeted defenses and lasting protection. This means antibody production is stimulated as B cells respond to the antigen, protection appears after exposure as the adaptive response develops, and the overall process is a direct result of the immune system’s activation. Vaccination and natural infection both trigger this kind of response, leading to immunological memory for long-term protection. Because all of these elements are true of active immunity, the description that fits best is all of the above.

Active immunity is when the body's own immune system mounts a response to a specific antigen, creating targeted defenses and lasting protection. This means antibody production is stimulated as B cells respond to the antigen, protection appears after exposure as the adaptive response develops, and the overall process is a direct result of the immune system’s activation. Vaccination and natural infection both trigger this kind of response, leading to immunological memory for long-term protection. Because all of these elements are true of active immunity, the description that fits best is all of the above.