Which of the following organisms is harmful to human beings?

Centipedes are venomous arthropods that can inflict painful bites on humans. Their modified front legs (forcipules) inject venom that can cause localized pain, swelling, and in some cases, systemic reactions. While millipedes are generally harmless (some produce irritating fluids), prawns are food sources, and cockroaches are disease vectors but not directly harmful through venom, centipedes pose the most direct physical threat through their venomous bite.