Final answer:
BGP (Border Gateway Protocol) uses a complex set of metrics called path vectors to exchange routing information among autonomous systems on the Internet.
Step-by-step explanation:
The routing protocol that uses a complex set of metrics called path vectors is c) BGP (Border Gateway Protocol). BGP is an exterior gateway protocol designed to exchange routing and reachability information among autonomous systems (AS) on the Internet. It uses path vector metrics to keep track of a route's path, various attributes, and policies applied, which makes it unique compared to other routing protocols such as RIP, OSPF, or EIGRP. This protocol is crucial for managing how packets get routed between different networks, making sure data travels along the best and most reliable pathways.