Which of the following devices can be used to connect multiple devices within broadcasting to every network port?

An unmanaged switch connects multiple devices and, by default, places all ports in a single broadcast domain. When a broadcast frame is received on one port, the switch floods that frame out all other ports within the same broadcast domain, effectively broadcasting to every network port that is part of that domain.

A hub repeats all incoming signals to every other port, effectively 'broadcasting' all traffic, but an unmanaged switch is a more modern and intelligent device that performs this function specifically for broadcast traffic while efficiently forwarding unicast frames.

A firewall is a security device that filters network traffic based on security rules, not primarily for connecting multiple devices or broadcasting to ports.

A cable modem provides internet connectivity from a cable provider and typically has only a few Ethernet ports, not designed for connecting multiple internal network devices within a local network.