D is correct:
[ ] - Brackets enclose the local AS number associated with the
AS path if configured on the router, or if AS path prepending
is configured.
{ } - Braces enclose AS sets, which are groups of AS numbers
in which the order does not matter. A set commonly results from
route aggregation. The numbers in each AS set are displayed in
ascending order.
( ) - Parentheses enclose a confederation.
( [ ] ) - Parentheses and brackets enclose a confederation set.
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easynet13
Highly Voted 7 months, 3 weeks agoak_sisko
Most Recent 3 months, 1 week agoGuru29
6 months, 2 weeks agoTurboMan85
7 months, 3 weeks ago