Question: What is the primary purpose of the ESM information request procedure initiated by the network during the attach procedure?
Option 1: To retrieve ESM information from the UE and provide privacy for this information when ciphering is enabled.
Option 2: To authenticate the UE before establishing a PDN connection.
Option 3: To inform the UE about available APNs in the network.
Option 4: To negotiate QoS parameters with the UE.
Explanation: The ESM information request procedure is used to retrieve protocol configuration options, APN, or both from the UE while ensuring privacy for this sensitive information by utilizing security protection if ciphering is enabled in the network.