Which Two Statements About Single-Hub DMVPN Are True? (Choose Two

Which two statements about single-hub DMVPN are true? (Choose two.)

A) Two spokes that are behind different NAT devices that both use PAT can establish a spoke-to-spoke connection.
B) DMVPN networks support GRE tunnel keepalives on point-to-point GRE tunnels.
C) Dynamic spoke-to-spoke tunnel connections support IKE certificates for ISAKMP authentication.
D) DMVPN networks support GRE tunnel keepalives on multipoint GRE tunnels.
E) Each DMVPN spoke requires a unique IP address after NAT translation.
F) Cisco best practices recommend that dynamic spoke-to-spoke tunnel connections use wildcard preshared keys for ISAKMP authentication