Correct Answer: A

Rationale: The correct answer is A: Identify and count cases. In the initial stages of an outbreak investigation, it is crucial to identify and count cases to understand the scope and magnitude of the outbreak. By counting cases, Nurse Rona and her team can track the spread of the disease, identify common characteristics among those affected, and determine the extent of the outbreak. This step helps in guiding further investigation and control measures. Summary of other choices: B: Define and identify cases - While defining cases is important, it is not the initial step in outbreak investigation. C: Verify diagnosis - Verifying diagnosis is important but comes after identifying and counting cases. D: Prepare for field work - Field work is important in outbreak investigations, but it typically comes after the initial step of identifying and counting cases.

Correct Answer: C

Rationale: The correct answer is C: Macrophages. Macrophages are antigen-presenting cells that engulf pathogens and present their antigens to T cells, initiating an immune response. They express major histocompatibility complex (MHC) molecules necessary for T cell recognition. B cells also present antigens but primarily to B cells for antibody production. NK cells are involved in killing infected cells, not antigen presentation. Eosinophils are mainly involved in allergic responses and defense against parasites, not antigen presentation.

Correct Answer: D

Rationale: The correct answer is D, Broad opening. Nurse Rica should use this communication technique to encourage the patient to freely express themselves without leading or interrupting. This technique helps build rapport and trust, setting a positive tone for the conversation. A: Clarifying may be too direct and might make the patient feel pressured. B: Challenging can create defensiveness and hinder open communication. C: Restating may not be as effective in initiating a conversation as broad opening. In summary, broad opening allows for a more open and relaxed conversation, fostering a conducive environment for effective communication with the patient.

Correct Answer: A

Rationale: The correct answer is A: Loss of self-tolerance. This is because autoimmune diseases result from a breakdown in the immune system's ability to distinguish between self and non-self antigens, leading to the production of antibodies against self-antigens. When self-tolerance is lost, immune cells mistakenly target the body's own tissues, causing tissue damage and inflammation. Choice B (Failure of innate immunity) is incorrect because autoimmune diseases are primarily driven by adaptive immunity rather than innate immunity. Choice C (Defective T cell activation) is incorrect as T cells play a critical role in the immune response to self-antigens in autoimmune diseases. Choice D (Impaired phagocytosis) is incorrect as phagocytosis is a mechanism primarily involved in the removal of pathogens, not in the development of autoimmune diseases.

Correct Answer: A

Rationale: Rationale: A is the correct answer as it demonstrates therapeutic communication by encouraging Annie to express her feelings and fears. It shows empathy and understanding, allowing Annie to elaborate on her concerns. B is incorrect as it dismisses Annie's fears and implies blame on her parenting. C is incorrect as it focuses on the behavior of the children rather than addressing Annie's emotions. D is incorrect as it places the responsibility on the children to make Annie feel comfortable, rather than addressing her concerns directly.