Which ports are commonly used to connect a computer to a modem or network?

The correct answer is the choice that refers to Ethernet ports. These ports are specifically designed to establish a connection between a computer and a modem or network. Ethernet ports support networking capabilities through Ethernet cables, which facilitate the transmission of data between devices on a local network as well as broader connections to the internet.

Ethernet technology is widely used in both home and enterprise networking contexts, enabling stable and fast data transfer. This makes them essential for wired internet connections and local area networks (LANs).

The alternative options serve different purposes: USB ports are mainly used for peripheral devices but can also support networking through specific adapters; HDMI ports are intended for video and audio output, primarily used to connect to displays; and FireWire ports were often used for connecting video cameras and external drives but are less common in modern networking contexts. Thus, Ethernet ports are the standard and most appropriate choice for connecting to modems and networks.