What routing protocol is the most popular distance-vector routing algorithm used to determine the best routes within a network?

A. RIPB. OSPFC. BGPD. IGMP

Routing Information Protocol (RIP) is the correct option.

Explanation:

Routing Information Protocol (RIP) is a dynamic routing protocol which is used to find the optimal path between the source and the destination. It is a distance vector routing protocol that works on application layer of OSI model. It uses hop count as a routing metric. Hop count is the number of routers that occurs on path towards the destination. Path with the minimum hop count is taken as the optimal route to reach a destination. This best path is then put in the routing table. RIP does not support more than 15 hops from source to destination. This is to avoid routing loop in the network RIP broadcasts updates related to routing information every 30 seconds. Routers using this protocol exchange entire routing tables with neighboring routers periodically. Easy to configure but has slow convergence as compared to other protocols.

Open Shortest Path First (OSPF) is a routing protocol used to find the optimal path between the source and the destination using Shortest Path First. It is a network layer protocol. Its a link state protocol not a distance vector routing protocol so its not a correct option.

Border Gateway Protocol (BGP) is intended to exchange information on routing and accessibility between autonomous systems over the Internet. It doesn't use distance vector routing but uses path vector routing instead, So its not a correct option.

IGMP (Internet Group Message Protocol) is a networking protocol used on IP networks for hosts and neighboring routers for forming memberships in multicast groups. IGMP works on the network layer. Its also not a correct option.