802.3bz is a standard for Ethernet over twisted pair at speeds of 2.5 and 5 Gbit/s. These use the same cabling as the ubiquitous Gigabit Ethernet, yet offer higher speeds. The resulting standards are named 2.5GBASE-T and 5GBASE-T.
Option A: 2.5Gb and 5Gb Ethernet ports
This is because option A shows how to identify the speed of an Ethernet port based on its name and the standard it supports. A port that supports 2.5GBASE-T or 5GBASE-T is a multi-gigabit port that can operate at speeds of up to 2.5 Gbit/s or 5 Gbit/s over twisted pair cables23.