All devices connected to an Ethernet hub are in the same ___ domain.

The correct answer is focused on the collision domain, which is essential for understanding how data transmission works in a shared network environment, particularly when discussing technologies like Ethernet hubs.

When devices are connected to an Ethernet hub, they share the same physical medium for communication. This means that when one device sends data, all the other devices connected to that hub receive the signal. The consequence of this shared communication medium is that if two devices attempt to send data simultaneously, a collision occurs. Because the Ethernet hub forwards signals to all ports, all devices connected to it are in the same collision domain. Thus, Ethernet hubs do not manage traffic efficiently, leading to increased chances of collisions and reduced overall network performance.

In contrast, other choices represent different network concepts. A broadcast domain generally refers to a logical division of a network where all nodes can reach each other by broadcast messages. Routing domains refer to paths within an IP network managed by routers. Finally, the term data domain typically does not relate specifically to Ethernet networking. Therefore, recognizing the specific context of the collision domain helps clarify why it is the appropriate term to use when discussing devices interconnected through an Ethernet hub.