You work as a Cisco engineer. You know Dynamic Host Configuration Protocol (DHCP) well, so
how are DHCP messages authenticated in the DHCP snooping process?

A.
Untrusted sources are identified by configuring their connecting interfaces.

B.
Traffic is blocked if it matches MAC addresses of invalid DHCP servers.

C.
Untrusted sources are matched against a database of valid Dynamic Host Configuration Protocol bindings.

D.
Trusted sources are matched by identifying RFC-consistent Dynamic Host Configuration Protocol calls.