Final answer:
The nurse should ask the child to pretend to blow up a balloon during the injection, which is a distraction method to reduce anxiety and discomfort associated with administering an immunization.
Step-by-step explanation:
When a nurse in a community health clinic is preparing to administer an immunization to a 5-year-old child, the best action for the nurse would be to c. Ask the child to pretend to blow up a balloon during the injection. This technique is a distraction method that can help in reducing the child’s anxiety and perception of pain associated with the procedure. While some of the other options involve medical treatments, such as using penicillin for managing Lyme disease or taking antibiotics for pertussis, they are not related to the specific context of administrating an immunization to a child.