Which routing protocol uses the Bellman-Ford algorithm?

Correct answer: RIPv2

Option B is correct because RIPv2 (Routing Information Protocol version 2) is a distance-vector routing protocol that uses the Bellman-Ford algorithm to calculate the shortest path to a destination based on hop count. Option A is incorrect because BGP (Border Gateway Protocol) is a path-vector protocol that uses a more complex best-path selection process involving attributes such as AS path, local preference, and MED, not Bellman-Ford. Option C is incorrect because IS-IS (Intermediate System to Intermediate System) is a link-state protocol that uses Dijkstra's Shortest Path First algorithm. Option D is incorrect because OSPF (Open Shortest Path First) is also a link-state protocol that uses Dijkstra's SPF algorithm rather than Bellman-Ford.