Question: Upon receiving an Aperiodic CSI Trigger State Subselection on a Serving Cell, what action is taken by the MAC entity according to specifications for Medium Access Control (MAC) protocol in 5G NR?
Option 1: The MAC entity ignores the message if it's not relevant to the currently active CSI process.
Option 2: The MAC entity indicates to lower layers the information regarding Aperiodic CSI Trigger State Subselection.
Option 3: The MAC entity automatically triggers a periodic CSI report back to the network.
Option 4: The MAC entity requests confirmation from the network before proceeding with the subselected state.
Explanation: This is correct because, upon receiving an Aperiodic CSI Trigger State Subselection on a Serving Cell, the MAC entity's defined action is to inform lower layers about the received subselection information, ensuring seamless adaptation for optimal channel state information (CSI) reporting in 5G networks.