Final answer:
The nurse should prioritize addressing the older adult's difficulty in remembering which medications they have taken during the day. Forgetting or taking medications incorrectly can have serious health consequences.
Step-by-step explanation:
The nurse should identify the priority problem as option d, 'I keep forgetting which medications I have taken during the day.' This issue is of immediate concern as it relates to the older adult's safety and well-being. Forgetting to take prescribed medications or taking them incorrectly can have serious health consequences. It is important for the nurse to assess the older adult's medication management and provide appropriate interventions to support their adherence to the medication regimen.