Final answer:
Greeting all patients by name is the best customer service action as it shows personalization and attentiveness to their needs.
Step-by-step explanation:
The best customer service action in this scenario would be 2) Greeting all patients by name. This action shows personalization and attentiveness to the patients' needs. By greeting patients by name, it creates a friendly and welcoming atmosphere, making them feel valued and important. This can improve the overall patient experience and satisfaction with the service provided.