Which IPv6 overlay tunnel statements are true ?

[PlAwAnSaI]

In this IPv6 network, an IPv6 overlay tunnel is required to communicate with
isolated IPv6 networks across the existing IPv4 infrastructure. There are currently five IPv6
overlay tunnel types.
Which three IPv6 overlay tunnel statements are true? (Choose three)
A. Overlay tunnels can only be configured between border routers capable of supporting IPv4
and IPv6.
B. An manual overlay tunnel supports point-to-multipoint tunnels capable of carrying IPv6 and
Connectionless Network Service (CLNS) packets.
C. Overlay tunneling encapsulates IPv6 packets in IPv4 packets for delivery across an IPv4
infrastructure.
D. Overlay tunnels can be configured between border routers or between a border router and
a host capable of supporting IPv4 and IPv6.
E. Cisco IOS supports manual, generic routing encapsulation (GRE), IPv4-compatible, 6to4,
and Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) overlay tunneling mechanisms .
F. Cisco IOS supports manual, generic routing encapsulation (GRE), IPv6-compatible, 4to6,
and Multiprotocol Label Switching (MPLS) overlay tunneling mechanisms.