Answer: c. ​peer-to-peer (P2P) networking
Explanation:
Peer-to-Peer (P2P) networking is a method of connecting computers to each other and sharing resources without having to use a central network server.
It can be a connection between two computers close to each other, a bunch of computers connected by USB or wired connections for instance or even computers around the world via the internet.
The Employees at Eco Engineering are therefore using P2P as they are sharing resources without having to go through a network server.