Final answer:
The best nurse's action would be to document the findings thoroughly in the patient's chart.
Step-by-step explanation:
The best nurse's action in this situation would be to document the findings thoroughly in the patient's chart (option B).
Brittle nails and hair, dry skin turgor, and muscle wasting are all signs of malnutrition. By documenting these findings, the nurse ensures that this important information is available to the healthcare team.
Options A, C, and D may be appropriate interventions for malnutrition, but they are not the best initial action to take. Referring the patient to Meals on Wheels, encouraging the patient to eat more, and consulting a postoperative dietitian are all steps that can be taken after the assessment has been documented and the healthcare team is aware of the patient's nutritional status.