What two statements are true about Oracle Enterprise Manager’s Java Diagnostic tool， which makes the tool suitable for production server diagnostics ？（）

• A、 virtually zero overhead for application running in the JVM 
• B、 no stalling of running JVM when taking a heap dump for memory analysis 
• C、 no need of modification， changes， or instrumentation of the application since is uses Network Protocol Analysis （NPA technology）
• D、 provides Byte Code Instrumentation for Java