Question: Which RLC transmission modes are supported for DRBs?
Option 1: Only Unacknowledged Mode (UM)
Option 2: Only Acknowledged Mode (AM)
Option 3: Either Unacknowledged Mode (UM) or Acknowledged Mode (AM)
Option 4: Transparent Mode (TM)
Explanation: The RLC sublayer supports three transmission modes, and for DRBs, either UM or AM mode can be used. This is because the RLC configuration is per logical channel with no dependency on numerologies and/or transmission durations, allowing flexibility in choosing the transmission mode for different types of data.