Which kind of connector do you use to connect a modem to a standard telephone line?

The RJ-11 connector is specifically designed for connecting devices to standard telephone lines. This type of connector typically has four or six pins and is commonly used for telephone equipment, including modems that dial into Internet Service Providers over analog phone lines. Given its design and functionality, the RJ-11 is compatible with the wiring used in traditional phone systems, making it the appropriate choice for establishing a connection between a modem and a telephone line.

In contrast, RJ-45 connectors are used for Ethernet networking, USB connections facilitate a variety of digital data transfers but are not applicable for phone lines, and HDMI is used for transmitting high-definition video and audio between devices. Each of these connectors serves very distinct purposes that do not relate to standard telephone connections.