When configuring site-to-site VPN High Availability (HA) with MEP, which of the following is correct?

When configuring site-to-site VPN High Availability (HA) with MEP, which of the following is correct?

A.
MEP Gateways cannot be geographically separated machines.

B.
The decision on which MEP Gateway to use is made on the MEP Gateway’s side of the tunnel.

C.
MEP Gateways must be managed by the same SmartCenter Server.

D.
If one MEP Security Gateway fails, the connection is lost and the backup Gateway picks up the next connection.