Answer:
The nurse should address the client statement:
b) "I am unable to sleep without medication."
This statement is a potential concern as it can impact the client's alertness and ability to drive safely. Medication-related issues, especially those affecting sleep, can significantly affect a person's cognitive function and reaction time, which are crucial for driving safely. Therefore, the nurse should prioritize addressing this statement to ensure the client's overall well-being and safety on the road.