Final answer:
The principle of advocacy is most beneficial in cases where a nurse needs to intervene with an insurance company on behalf of a patient's surgery coverage, as it involves actively supporting the patient's healthcare needs.
Step-by-step explanation:
The ethical principle most beneficial to a patient in this situation is advocacy. When a nurse discovers that a patient's insurance company is not providing clear information regarding coverage for surgery, advocating on behalf of the patient helps to ensure that they receive the care and support they need. This advocacy involves communicating with the insurance company to clarify coverage details, ensuring that the patient understands their rights and options, and potentially seeking alternative solutions to support the patient's healthcare needs. It aligns with the broader ethical concept of justice, which demands fair and equitable treatment in healthcare settings, but advocacy focuses on active support and representation of the patient's interests.