What is the purpose of an edge node in an SD-Access network fabric?

What is the purpose of an edge node in an SD-Access network fabric?
A . Edge nodes identify and authenticate endpoints and register endpoint information with control plane nodes.
B . Edge nodes track endpoint IDs to location mappings, along with IPv4, IPv6, or MAC addresses.
C . Edge nodes are the gateway between the fabric domain and network outside of the fabric.
D . Edge nodes resolve lookup requests from edge and border nodes to locate destination endpoint IDs.

Answer: A