Question

a booster ____________. a raises the antibody titer b contains antibodies against the pathogen it protects against c is an example of natural immunity d is an example of passive immunity

Explanation:

• Option A: A booster shot (vaccine booster) is given to increase the antibody titer (level of antibodies) in the body, enhancing immunity.
• Option B: Boosters typically contain antigens (not pre - formed antibodies) to stimulate the immune system.
• Option C: Boosters are artificial (vaccination - induced), not natural immunity.
• Option D: Boosters induce active immunity (body produces antibodies), not passive (which involves receiving antibodies).

Answer:

A. raises the antibody titer