Final answer:
CAT5 / CAT5e is the Twisted-Pair cable that uses 100Mhz signaling, suitable for networks operating at 10/100 Mbps. CAT6 and CAT6a support higher frequencies and are used for faster network speeds, while CAT4 is outdated with lower frequency support.
Step-by-step explanation:
The Twisted-Pair cable that uses 100Mhz signaling is CAT5 / CAT5e.
CAT5 and CAT5e cables are designed to support frequencies up to 100Mhz, making them suitable for networks operating at 10/100 Mbps.
CAT6 cables can handle up to 250Mhz while CAT6a cables are capable of up to 500Mhz, and are generally used for networks with higher speed requirements.
CAT4 cables, on the other hand, were designed for frequencies up to only 20Mhz.