Final answer:
The nurse must respect the client's autonomy and provide education on the risks associated with refusing treatment for pneumonia, while not physically restraining or forcibly keeping the client against their will.
Step-by-step explanation:
When a client in acute respiratory distress from pneumonia refuses to stay for treatment, it is primarily the nurse's responsibility to respect the client's autonomy while ensuring that the client is well-informed about the risks and consequences of refusing treatment. The nurse should provide education regarding the benefits of staying for treatment and the possible dangers of leaving without treatment. However, physically restraining the client or involving security would violate the principle of autonomy and informed consent, both of which are foundational to ethical healthcare practice. Furthermore, informing the client's family without the client's consent may breach patient confidentiality unless the situation warrants it due to implied consent or a life-threatening emergency. Thus, the correct course of action is option A) Respect the client's autonomy while providing education on the risks.