Final answer:
PSTN is the technology used to connect public networks using POTS lines.
Step-by-step explanation:
The technology used to connect public networks using POTS lines is PSTN (Public Switched Telephone Network). PSTN is a traditional telecommunications network that uses copper wires and circuit-switching to transmit voice and data.
Unlike OC3, Cable, and OC12 which are all different types of network technologies, PSTN is specifically designed for POTS lines.