Question: What triggers the measurement of attempted reconfigurations of LTE DRB to LWA DRB?
Option 1: Transmission of RRCConnectionReconfiguration message by the UE
Option 2: Transmission of RRCConnectionReconfiguration message which includes the drb-ToAddModList in the radioResourceConfigDedicated information element by the eNB, and the drb-ToAddModList contains at least one drb-Identity that is part of the current UE configuration but not an LWA DRB and the drb-TypeLWA of this DRB set to TRUE
Option 3: Receipt of RRCConnectionReconfiguration message by the UE
Option 4: Handover from LTE to WLAN
Explanation: The correct answer is Option 2 because, according to the text, the measurement is triggered when the eNB transmits an RRCConnectionReconfiguration message that includes a drb-ToAddModList with at least one DRB identity that is part of the current UE configuration but not an LWA DRB and has its drb-TypeLWA set to TRUE. This specific condition indicates an attempted reconfiguration from LTE DRB to LWA DRB.