Rationale: A. Applying antibiotic ointment to mucous membranes is not a standard or effective intervention for preventing systemic infection or septic shock. Prophylactic topical antibiotics do not reduce the risk of urosepsis and may contribute to antimicrobial resistance. B. Passive range-of-motion exercises promote mobility and circulation but do not directly reduce the risk of infection progression or septic shock. They are supportive measures rather than infection-prevention strategies. C. Initiating total parenteral nutrition may be necessary in some clients who cannot meet nutritional needs enterally, but it does not directly reduce the risk of septic shock. In fact, TPN itself can increase infection risk if central venous access is required. D. Invasive devices, such as urinary catheters and central lines, are common sources of infection. Removing them as soon as they are no longer needed significantly reduces the risk of healthcare-associated infections and progression to sepsis or septic shock, making this the most effective preventive action.