If an operating system does not allow a child process to exist when the parent…

Answer: Cascading termination

Explanation: Cascading termination means that when a parent process is terminated, the operating system also terminates its child processes, so termination cascades down the process tree.

• Key point: The child processes do not continue running independently; they are automatically stopped when the parent ends.

• Contrast with a zombie process: A zombie is a child that has finished but remains in the process table because the parent has not yet collected its exit status.

• Contrast with threading: Threading involves multiple threads inside the same process and is unrelated to parent-child process termination behavior.

• Contrast with process killing: Process killing is a general action of terminating a process and does not specifically describe automatic termination of child processes when the parent dies.