Question: What is the primary trigger for detecting a Transfer Syntax Error in UTRAN Iu interface RANAP signalling, according to 3GPP standards?
Option 1: Failure to authenticate User Equipment (UE) during initial access
Option 2: Successful decoding of an ASN.1 message with out-of-range values
Option 3: Receipt of a physical message that cannot be decoded during the ASN.1 decoding process
Option 4: Expiration of a timer set for a response to a RANAP message
Explanation: A Transfer Syntax Error is specifically related to the inability to decode received messages, which directly points to issues encountered during the decoding process. Among the provided options, only Option 3 accurately describes this scenario - the failure to decode a physical message during ASN.1 decoding, aligning with the definition of Transfer Syntax Errors as per the extracted context.