What are the two key elements that Identity works by?

The correct choice highlights the significance of the ID itself and the institution that uses the ID as the two key elements that identity works by. In healthcare systems, specifically those utilizing electronic health records and identity management, each patient is assigned a unique identifier, which is crucial for tracking their medical information accurately throughout different institutions and services.

In this context, the ID serves as a primary means of establishing a patient's identity, ensuring that their records are linked correctly to them. The corresponding institution plays a vital role because it is responsible for managing and maintaining that identity within its systems. This ensures that patient data integrity is preserved, as it allows for the appropriate linking of patient records across various departments, services, and locations.

Thus, the concept of identity management in healthcare is effectively encompassed by these two elements, making it essential for secure and accurate patient care.