Question: What triggers the increment of the "Number of SN terminated bearers Path Update at Secondary Node Additions" measurement?
Option 1: When the MME receives an E-RAB modification indication message from the MN at Primary Node Additions.
Option 2: On transmission by the MN of a handover request to the target eNodeB during an inter-eNB handover.
Option 3: On transmission by the MN of an E-RAB modification indication message to MME at Secondary Node Additions with SN terminated bearers.
Option 4: When the SGNB Addition Trigger Indication includes a SN change or inter-eNB HO.
Explanation: The correct answer is Option 3 because, according to the text, the measurement is incremented when the MN transmits an E-RAB modification indication message to MME at Secondary Node Additions with SN terminated bearers. This specific scenario triggers the increment of the "Number of SN terminated bearers Path Update at Secondary Node Additions" measurement.