Question: Under what circumstances is the Criticality Diagnostics Information Element (IE) typically sent over the UTRAN Iu interface by either the Radio Network Controller (RNC) or the Core Network (CN)?
Option 1: When a message is successfully processed without errors, to confirm receipt.
Option 2: When parts of a received message cannot be understood, are missing, or contain logical errors.
Option 3: During routine network maintenance to test signaling pathways.
Option 4: Exclusively for messages related to handover procedures between different RNCs.
Explanation: The Criticality Diagnostics IE is utilized as a diagnostic tool to indicate issues with message comprehension or integrity, specifically sent when received messages have problems like incomprehensible, missing, or logically erroneous components, aiding in error identification and potentially facilitating corrective actions.