Cascading termination refers to a termination of all child processes, if the…

Concept: Cascading termination is an OS process-management policy — when a parent process's entry is removed from the process table, every process still recorded as its child is also terminated, so no child is left running without a supervising parent (avoiding orphan processes).

Applying it here: a parent's process-table entry can be removed in two ways — it can finish its own work and exit on its own (a normal exit), or it can be killed by a signal or crash due to an error (an abnormal exit). Cascading termination is triggered by the entry being removed, not by which of these two paths caused the removal, so it fires in both cases here.

• "Abnormally" only accounts for the crash/signal path and misses that a clean, successful exit removes the same process-table entry and triggers the same cleanup.

• "Normally" only accounts for the clean-exit path and misses that a crash or forced kill removes the same entry through the same mechanism.

• "None of the mentioned" is wrong because operating systems define this exact cascading-termination policy explicitly — a governing condition does exist.