which portion is interpreted by IS-IS as the area?

Given the NSAP, 39.0100.0102.0001.0c00.1211.00, which portion is interpreted by IS-IS as the
area?

A.
39.0100

B.
39

C.
0001.0c00

D.
0001.0c00.1211

E.
39.0100.0102

F.
0001