Final answer:
RIP (Routing Information Protocol) is limited to smaller networks due to its limitation of 15 hops, making it unsuitable for larger network implementations compared to OSPF, EIGRP, and BGP.
Step-by-step explanation:
The routing protocol that is limited to smaller network implementations and does not scale well for larger networks is A) RIP (Routing Information Protocol). RIP uses a distance-vector routing algorithm, which is suitable for small to medium-sized networks. However, because it limits the number of hops to 15 by default, it is not optimal for larger networks; this hop limit prevents RIP from effectively managing routing in larger or more complex topologies. In contrast, OSPF (Open Shortest Path First) and EIGRP (Enhanced Interior Gateway Routing Protocol) are designed to scale for larger networks due to their advanced algorithms and hierarchical design. BGP (Border Gateway Protocol) is used for routing between autonomous systems on the Internet and is also designed to handle large-scale networks.