OSPF routing uses the concept of areas. What are the characteristics of OSPF areas? (Choose three.)
A.
Each OSPF area requires a loopback interface to be configured.
B.
Areas may be assigned any number from 0 to 65535.
C.
Area 0 is called the backbone area.
D.
Hierarchical OSPF networks do not require multiple areas.
E.
Multiple OSPF areas must connect to area 0.
F.
Single area OSPF networks must be configured in area 1.
no i don’t agree with option B.As we know that the range of area ID is between 0-4.2 billion.It do fall in the range 1-65535,but again contradiction ie. area ID starts from zero(0).
So the best answer is C D E.refer Todd Lammle(5th edition ,page 336,question no. 8)