Final answer:
A child process that has finished executing but whose parent process does not acknowledge the completion is known as a zombie process.
Step-by-step explanation:
The child process referenced in the question becomes known as a zombie process. This occurs when the child process has completed executing, but its parent process continues to run without acknowledging the completion of the child. In more technical terms, the child process has finished execution and has returned an exit status, but it still has an entry in the process table. This entry is used to store the exit status of the child process so that the parent process can retrieve it. The child remains in a "zombie" state until its parent process reads the exit status, at which point it is fully terminated and its record in the process table is removed. As for the other options: an 'orphan' process has a living parent process that does not wait for it to exit, a 'dead' process has been fully terminated, and 'body' is not a term used in this context.