Final answer:
The correct answer is D. Role model. A charge nurse serving as a mentor is a role model for the less experienced nurse.
Step-by-step explanation:
The correct answer is D. Role model. Serving as a mentor to another staff nurse who is less experienced involves being a role model for them to learn from. A charge nurse in this role would set an example of professionalism, clinical skills, and leadership for the less experienced nurse to follow.