You wish to kill a process with a PID of 123. Select the command which exiting.

A.
kill-1 123

B.
kill-9 123

C.
kill-15 123

D.
kill-17 123

Explanation:
To terminate the process we use kill command. But we should know the process ID. In questions
PID is specified to 123.
Syntax of kill command is: kill signal PID
Where -9 is the powerful signal then other signal which kill the process.