Option B isfalse. By default, when the aggregate command is usedwithout any options, BGP generates asummary route, andsuppresses the specific routesthat fall under that summary. To advertise both specific and summary routes, you mustexplicitly configurethe detail-suppressed option to control whether specifics are suppressed or not.
Explanation of the other options:
Ais correct: When suppress-policy is specified, only specific routes matching the policy are advertised; others are suppressed.
Cis correct: The summary automatic command causes summarization based on classful boundaries, which is a legacy behavior.
Dis correct: With detail-suppressed, only the summary route is advertised, not specific prefixes.
Reference from Huawei HCIP-Datacom-Core Technology Study Guide:
“The aggregate command suppresses specific routes by default unless explicitly configured otherwise. Use of suppress-policy or detail-suppressed allows control over which routes are advertised.”
(Chapter: BGP Advanced Features – Section: Route Aggregation)