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

B.
39.0100

C.
39.0100.0102

D.
0001

E.
0001.0c00

F.
0001.0c00.1211

Explanation: