Which cable standard is backwards compatible with USB 1.1?

USB 2.0 is the correct answer because it was designed with backward compatibility in mind, meaning that devices that use USB 1.1 can still function with USB 2.0 ports and vice versa. This compatibility allows users to connect older devices, such as keyboards, mice, and printers that were designed for USB 1.1, to newer hardware that uses USB 2.0, without requiring any special adapters or converters.

USB 3.0, while also backward compatible with USB 2.0 and USB 1.1 devices, is primarily a higher-speed standard that introduced additional capabilities. However, the question specifically asks for the standard that directly ensures compatibility with USB 1.1, which USB 2.0 does explicitly.

USB 4.0 also maintains backward compatibility but is a more recent standard that focuses on supporting both USB and Thunderbolt devices at much higher transfer speeds. Thunderbolt is a separate technology designed for high-speed data transfer and does not guarantee direct compatibility with the USB 1.1 standard, as it is not based exclusively on USB specifications.