Which of the following answers is most true about the BGP Update message?（）

• A、It lists a set of path attributes, along with a list of prefixes that use those PAs
• B、It lists a prefix/length, plus the PA settings for that prefix
• C、It  lists withdrawn routes, but never in the same Update message as newly advertised routes
• D、A single Update message lists at most a single prefix/lengtH