BGP (Border Gateway Protocol) is the only dynamic routing protocol used across the internet. It's classified as an Exterior Gateway Protocol (EGP), responsible for routing between different autonomous systems (ASes).
A). EIGRP and D. OSPF are Interior Gateway Protocols (IGPs), used within organizations.
C). RIP is an outdated IGP with limited use, unsuitable for internet-scale routing.
# Reference:
CompTIA Network+ N10-009 Official Objectives: 3.1 - Compare and contrast various routing technologies.