Which two options describe how 6RD compares to automatic 6to4 tunneling? (Choose two.)

A.
6RD provides a controlled exit point from the IPv6 Internet.

B.
6RD provides a controlled entry point to the IPv6 Internet.

C.
6RD is widely available in current OS implementations.

D.
Automatic 6to4 tunneling is widely available in current OS implementations.

E.
Automatic 6to4 tunneling and 6RD use a well-known IPv6 prefix.