The session status for an IPsec tunnel with IPv6-in-IPv4 is down with the error message IKE
message from 10.10.1.1 failed its sanity check or is malformed.
Which statement describes a possible cause of this error?

A.
There is a verification failure on the IPsec packet.

B.
The SA has expired or has been cleared.

C.
The pre-shared keys on the peers are mismatched.

D.
There is a failure due to a transform set mismatch.

E.
An incorrect packet was sent by an IPsec peer.