You are troubleshooting a site-to-site VPN issue where the tunnel is not establishing. After
issuing the debug crypto isakmp command on the headend router,you see the following
output. What does this output suggest?
1d00h: ISAKMP (0:1): atts are not acceptable. Next payload is 0
1d00h: ISAKMP (0:1); no offers accepted!
1d00h: ISAKMP (0:1): SA not acceptable!
1d00h: %CRYPTO-6-IKMP_MODE_FAILURE. Processing of Main Mode failed with peer at
10.10.10.10

A.
Phase 1 policy does not match on both sides.

B.
The transform set does not match on both sides.

C.
ISAKMP is not enabled on the remote peer.

D.
There is a mismatch in the ACL that identifies interesting traffic.