OSPF is considered to be an extremely scalable routing protocol. Which of the following would be reasons for this? (Select two)
A. Neighbor adjacencies control distribution of routing protocol updates.
B. Routing table information does not flood the network until holddown timers have expired.
C. The hello protocol is a more efficient means of sending routing updates than table exchange used in RIPv1.
D. Topological database is maintained with incremental updates, with full exchange occurring only every 30 minutes.