A process is called a zombie process, if it is terminated but it's entry still exists in the Process Table, because it has to pass it's exit status to the the parent process
=> Only a terminated process can be a zombie process, which makes Option A our answer.
Processes C and D can't be zombie processes as they're not yet terminated. Process P can't be an orphan, as nowhere it is mentioned that it's parent has terminated.
Source: Galvin, page 121.