Question: What does a `FeatureSetEUTRA-DownlinkId` value of 0 indicate in relation to a UE's (User Equipment) capabilities in E-UTRA?
Option 1: The UE supports the latest downlink feature set in E-UTRA.
Option 2: The UE is operating in a specific low-power mode for downlink communications.
Option 3: The UE does not support any carrier in the specified band or band combination for downlink.
Option 4: The UE requires additional signaling to determine its downlink feature set support.
Explanation: A `FeatureSetEUTRA-DownlinkId` value of 0 indicates that the User Equipment (UE) does not support a carrier in the band or band combination for downlink communications, aiding in optimizing network resource allocation and enhancing overall network performance.