How many pairs of wires are used in a 100BASE-T cable?

A 100BASE-T cable uses two pairs of wires, which is a key characteristic of its design. The 100BASE-T standard, specifically 100BASE-TX, operates over twisted pair cabling and requires two pairs of wires to transmit and receive data simultaneously.

In this context, one pair is used for transmitting data, while the other pair is used for receiving data, allowing for full-duplex communication. This ability to send and receive data concurrently contributes to the cable's efficiency and speed, supporting transmission speeds of up to 100 Mbps.

Standard Ethernet implementations, such as 10BASE-T or 100BASE-T, utilize the same types of cabling but vary in their number of pairs needed for operation. For instance, in 10BASE-T, only one pair is used for communication, while 100BASE-T employs two pairs, highlighting the enhanced data capacity as transmission standards evolved.

The remaining choices either suggest an insufficient number of pairs or overstate the requirement, considering 100BASE-T's specific functionality designed for higher speeds and efficient data handling.