What roles do the Designated Router (DR) and Backup Designated Router (BDR) play in OSPF?

What roles do the Designated Router (DR) and Backup Designated Router (BDR) play in OSPF?
A . They redistribute routes between OSPF and non-OSPF networks.
B . They are responsible for generating LSAs for external routes.
C . They reduce the number of adjacencies on broadcast networks.
D . They determine the shortest path first algorithm.

Answer: C