Which of the Following Statements Regarding BGP Route Reflectors (RRs)

Which of the following statements regarding BGP route reflectors (RRs) are true?

A) An RR advertises routes learned from a client to all connected non-clients and clients.
B) A backbone network is divided into multiple reflection clusters. Each RR is configured as a non-client of the other RR, and establishes full-mesh IBGP connections with each other.
C) Cluster_List is an optional non-transitive attribute and is used to prevent loops in a cluster.
D) The Originator_ID attributes is generated by an RR to prevent loops between clusters.