Which tool is based on the AIX trace facility？（）

A. chdev
B. cfgmgr
C. vmtune
D. schedtune

A. ping and arp
B. lsattr and ifconfig
C. netstat and iostat
D. iptrace and tcpdump

A. It is a pseudo filesystem that maps processes and kernel data structures to corresponding files.
B. It is a JFS mounted filesystem that provides an exact representation of what is happening to a proces at a single and discrete point of time.
C. It is a JFS mounted filesystem that maps processes and read-only files related to these processes.
D. It is a pseudo filesystem that contains data that represents the state of the parent processes （but not their threads） in a system.