Question: How is ECN marking for L4S enabled in NG-RAN?
Option 1: Through a coordinated configuration in NG-RAN and 5GC, based on predefined PCC rules.
Option 2: By the SMF instructing NG-RAN to provide an indication for ECN marking for L4S, based on dynamic or predefined PCC rules.
Option 3: Automatically by NG-RAN, without any instruction from the SMF or 5GC.
Option 4: Only through dedicated QoS Flow(s) carrying L4S enabled IP traffic.
Explanation: The correct answer is Option 2 because the paragraph states that "The SMF may be instructed... to provide an indication for ECN marking for L4S to NG-RAN..." which indicates that the SMF plays a role in enabling ECN marking for L4S in NG-RAN. This option highlights the importance of the SMF's instruction in enabling ECN marking for L4S, demonstrating a nuanced understanding of the 5G system architecture.