Question: Over E-UTRAN, which Signalling Radio Bearer (SRB) is used for the DLInformationTransfer message when it only includes `dedicatedInfoF1c` information?
Option 1: SRB1, regardless of whether SRB2 is established or suspended
Option 2: SRB2, if established; otherwise, SRB1 until SRB2 is resumed
Option 3: SRB1, only for UEs that have not yet established an RRC connection
Option 4: SRB2, exclusively for `dedicatedInfoF1c` information transfer
Explanation: According to the specifications for DLInformationTransfer message handling in E-UTRAN, when the message only includes `dedicatedInfoF1c` (IAB-DU specific F1-C related information), it is mandated to use SRB2. This ensures that such dedicated information is transferred over the more suitable bearer for its type, highlighting the importance of proper bearer selection for efficient and targeted data transfer in telecom networks.