Which command-line tool is known as the 'Swiss Army knife' of networking, capable of creating TCP/UDP connections, listening on ports, and transferring data?

Why C is correct

Netcat (nc) creates arbitrary TCP/UDP connections. Uses: port scanning (nc -zv host 1-1000), file transfer (nc -l 1234 > file), chat (nc host 1234), banner grabbing, and creating reverse/bind shells. It's invaluable for network debugging, pentesting, and quick data transfer.