A. Determining the need for urinary catheterization is within the scope of a registered nurse (RN), as it involves assessment and clinical judgment. A practical nurse (PN) does not independently determine the need for catheterization. B. Titrating oxygen within prescribed parameters is an appropriate task for a PN, as it involves following provider orders and monitoring the client's response while working under RN supervision. C. Receiving a postoperative client and conducting the initial assessment requires comprehensive assessment skills, which fall within the RN's scope of practice rather than the PN's. D. Evaluating and updating plans of care require critical thinking and clinical decision-making, which are responsibilities of the RN. The PN can contribute to care but does not independently evaluate or modify care plans.