Question: In the context of interworking between HRPD (High Rate Packet Data) and E-UTRAN (Evolved Universal Terrestrial Radio Access Network), what assumption is made regarding security context exchange during both idle and active mode mobility?
Option 1: No security context exchange is performed between E-UTRAN and HRPD access systems.
Option 2: Security context exchange is mandatory for all active mode mobility scenarios.
Option 3: Periodic security context exchanges are required every hour in idle mode.
Option 4: Security context exchange is only performed during initial attachment to E-UTRAN from HRPD.
Explanation: This correct answer reflects the specified assumption for interworking security between HRPD and E-UTRAN, emphasizing that no exchange of security contexts occurs. This is crucial for understanding the security framework in place for mobility scenarios between these two access systems, highlighting a reliance on other security mechanisms to ensure protection.