The correct answer is D. Peripheral nervous system.
When you stub your big toe on the chair leg, the initial pain message is transmitted through the peripheral nervous system. The peripheral nervous system includes all the nerves that extend from the brain and spinal cord to the rest of the body, including sensory nerves that carry information from the body's periphery (such as the toe) to the central nervous system.
These sensory nerves are responsible for detecting and transmitting the pain signal to the brain. The central nervous system (option B) processes and interprets this information, while the autonomic nervous system (option C) and sympathetic division (option A) are more involved in regulating involuntary bodily functions and responding to stress. Therefore, The correct answer is D. Peripheral nervous system.