Question: What is the primary function of the IAB-node in relation to downstream IAB-nodes and UEs?
Option 1: To provide wireless backhaul via the S1 interface.
Option 2: To manage the context of IAB-MT via the F1-C interface.
Option 3: To provide wireless backhaul via the network functionalities of the NR Uu interface (named IAB-DU function of IAB-node).
Option 4: To connect to an upstream IAB-node or an IAB-donor-DU via the X2 interface.
Explanation: The correct answer is Option 3 because, according to the text, the IAB-node provides wireless backhaul to downstream IAB-nodes and UEs via the network functionalities of the NR Uu interface (named IAB-DU function of IAB-node). This highlights the role of IAB-node in providing wireless connectivity to downstream nodes and UEs.