Final answer:
Tracy's ability to recover from chicken pox with minimal treatment or medication is due to the innate immune response in her body.
Step-by-step explanation:
The subject of this question is Biology. The question is asking about the line of defense involved in Tracy's ability to recover from chicken pox with minimal treatment or medication. The correct answer is the innate immune response, which is responsible for the initial defense against pathogens and does not require prior exposure to the specific pathogen.
Learn more about Immunity and Preventing Disease