Question: What is the primary purpose of the Purge function in the context of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access?
Option 1: To update the subscription data of an attached User Equipment (UE).
Option 2: To notify the Home Subscriber Server (HSS) that a UE has initiated an attach procedure.
Option 3: To inform the HSS that the Mobility Management Entity (MME) has deleted the subscription data and MM context of a detached UE.
Option 4: To request the HSS to provide the MME with updated subscription data for a UE.
Explanation: The Purge function is used by the MME to notify the HSS that it has deleted the subscription data and MM context of a detached UE, allowing the HSS to update its records accordingly. This ensures consistency between the MME and HSS regarding the UE's state.