An administrator needs to kill the oldest Bash shell running in the system. Which of the following commands should be issued to accomplish this task?
A. ps axjf | grep bash to obtain PID kill -9 PID
B. ps -eo pid,etime,cmd | grep bash (to obtain PID) kill -9 PID
C. ps -eo pid,etime| grep bash (to obtain PID) killall -9 PID
D. killall -15 -o bash
