Which particular skeletal muscle if they where paralyzed by botulinum would stop the victim from breathing?

If the diaphragm, the primary muscle responsible for breathing, were paralyzed by botulinum toxin, the victim would be unable to breathe effectively. The diaphragm contracts to create negative pressure in the thoracic cavity, allowing air to flow into the lungs. Paralysis of this muscle would lead to respiratory failure, as the body would struggle to take in oxygen and expel carbon dioxide.