Question: What happens to the DRB when the gNB decides to release the corresponding QFI to DRB mapping rule in the process of releasing a QoS flow with explicit NAS signalling?
Option 1: The DRB is released immediately after the QFI to DRB mapping rule is removed.
Option 2: The DRB remains unchanged and continues to carry other QoS flows.
Option 3: The gNB sends an RRCReconfiguration message to UE to release the DRB.
Option 4: The DRB is temporarily suspended until all QoS flows are released.
Explanation: According to the provided text, when the gNB decides to release the corresponding QFI to DRB mapping rule (step 2), it does not release the DRB because the DRB also carries other QoS flows. This indicates that the DRB remains unchanged and continues to carry other QoS flows, making option 2 the correct answer.