Question: What triggers the measurement of attempted reconfigurations of LTE DRB to LWIP DRB?
Option 1: Transmission of RRCConnectionReconfiguration message with drb-ToAddModList containing at least one LTE DRB of the current UE configuration and the drb-TypeLWIP set to "eutran".
Option 2: Transmission of RRCConnectionReconfiguration message which includes the drb-ToAddModList in the radioResourceConfigDedicated information element, and the drb-ToAddModList contains at least one drb-Identity that is an LTE DRB of the current UE configuration and the drb-TypeLWIP of this DRB is included and not set to "eutran".
Option 3: Receipt of RRCConnectionReconfiguration message with drb-ToAddModList containing at least one LTE DRB of the current UE configuration.
Option 4: Successful reconfiguration of LTE DRB to LWIP DRB.
Explanation: The correct answer is Option 2 because it accurately describes the condition that triggers the measurement, as specified in the 3GPP TS 32.425 standard. This option correctly states that the transmission of RRCConnectionReconfiguration message with specific conditions (drb-ToAddModList containing at least one LTE DRB and drb-TypeLWIP not set to "eutran") is what triggers the measurement of attempted reconfigurations of LTE DRB to LWIP DRB.