Answer :
The statement that is not true about hubs is D. Hubs are data link layer devices that connect network devices in a star or ring topology.
At the physical layer of the OSI model, hubs allow signals to be transmitted between devices that are connected to one another within a network. They don't take part in error control or logical addressing.
Hubs exclusively support a star network topology, where each device connects directly to the hub. Therefore, while hubs amplify and repeat signals in a star configuration, they do not operate at the data link layer or support ring topologies.