Question: In LTE-WLAN Aggregation (LWA), when a User Equipment (UE) receives an LWAAP (LTE-WLAN Aggregation Adaptation Protocol) data Service Data Unit (SDU) from upper layers, what are the correct sequential steps taken by the LWAAP entity in the UE?
Option 1: - Deliver the LWAAP SDU to lower layers without modification.
  - Identify the DRB (Data Radio Bearer) ID of the originating upper layer entity.
  - Assemble the LWAAP data PDU by adding a header.
Option 2: - Modify the LWAAP SDU based on bearer type before processing.
  - Deliver the assembled LWAAP data PDU to lower layers.
  - Identify the DRB ID of the upper layer entity.
Option 3: - Encrypt the LWAAP SDU for security before assembly.
  - Assemble the LWAAP data PDU from the LWAAP SDU by adding the LWAAP header.
  - Deliver the encrypted SDU to lower layers.
Option 4: - Identify the DRB ID of the upper layer entity from which the LWAAP SDU is received.
  - Assemble the LWAAP data PDU from the LWAAP SDU by adding the LWAAP header.
  - Deliver the assembled LWAAP data PDU to the lower layers.
Explanation: This sequence aligns with the standardized procedure for handling LWAAP data in LTE-WLAN Aggregation, ensuring proper identification of the data source (via DRB ID), correct formatting for transmission (by adding the LWAAP header), and timely delivery to lower layers for further processing and forwarding. This process is crucial for efficient and accurate data transfer in aggregated network environments.