Implementing Cisco IP Switched Networks (SWITCH v2-0) (#74)

Which statement about Cisco devices learning about each other through Cisco Discovery Protocol is true?

Each device sends periodic advertisements to multicast address 01:00:0C:CC:CC:CC.
Each device broadcasts periodic advertisements to all of its neighbors.
Each device sends periodic advertisements to a central device that builds the network topology.
Each device sends periodic advertisements to all IP addresses in its ARP table.