A client is immunocompromised. What is the nurse's priority action for this client?

Choice A reason: Determining the duration of the immunocompromised state (e.g., whether it is due to transient chemotherapy or a permanent primary immunodeficiency) is part of a comprehensive assessment and care plan. However, this is a theoretical or long-term classification task that does not provide the immediate, life-saving protection required for the patient's safety. Choice B reason: Frequent temperature monitoring is essential for detecting the early stages of neutropenic fever or sepsis in an immunocompromised patient. While this is a critical assessment, it is a reactive measure used to detect an infection that may already be present. Primary prevention of infection is always a higher clinical priority than detection. Choice C reason: Encouraging family members to be vaccinated is a vital component of "cocooning" the patient to prevent the transmission of viral pathogens. While this is an important discharge teaching and long-term health promotion strategy, it is not the most immediate priority for a nurse providing direct care in the clinical environment. Choice D reason: Hand hygiene is the single most effective intervention for preventing the transmission of healthcare-associated infections. For an immunocompromised client, the priority is to prevent the introduction of opportunistic pathogens. Strict adherence to handwashing protocols before entering the room provides the most immediate and direct protection against life-threatening infections.