Which two statements about IPv6 6to4 tunnels are true?

Which two statements about IPv6 6to4 tunnels are true? (Choose two)
A. Sites use addresses from the 2002:716 prefix
B. Sites use addresses from link-local scope
C. They are point-to-multipoint tunnels
D. They are point-to-point tunnels
E. They rely on GRE encapsulation