The Federated Model of Health Information Exchange Architecture Is Best

The federated model of health information exchange architecture is best described as a model in which:

A) data resides only within each institution's system and the health information exchange database houses only a master patient index with unique patient identifiers.
B) all participating institutions agree to purchase their health information software from the same vendor.
C) patient data is maintained under control of federal regulations.
D) all participating institutions periodically send copies of clinical data to one central repository where all data reside together in one format.