Question: What triggers the measurement of 'Attempted dynamic PDP context activation procedures initiated by MS' in a Core Network (CN) Packet Switched (PS) domain?
Option 1: Receipt of an 'Activate PDP Context Request' message from the User Equipment (UE) with an empty PDP address.
Option 2: Successful establishment of a new PDP context for a dynamic IP address allocation.
Option 3: Rejection of a 'Modify PDP Context Request' due to insufficient resources.
Option 4: Expiration of an existing PDP context's lifetime.
Explanation: This is correct because the measurement is specifically triggered by the receipt of an 'Activate PDP Context Request' from the Mobile Station (MS) with an empty PDP address, indicating a request for dynamic PDP address allocation.