Which two statements are true regarding the usage of multiple authentication keys?

EIGRP allows configuration of multiple MD5 keys for packet authentication to support easy rollover
from an old key to a new key. Which two statements are true regarding the usage of multiple
authentication keys? (Choose two.)

A.
Received packets are authenticated by the key with the smallest key ID.

B.
Sent packets are authenticated by all valid keys, which means that each packet is replicated as
many times as the number of existing valid keys.

C.
Received packets are authenticated by any valid key that is chosen.

D.
Sent packets are authenticated by the key with the smallest key ID.