Final answer:
The feature specific to the sympathetic nervous system is that its preganglionic neurons originate in the thoracolumbar spinal cord.
Step-by-step explanation:
The correct answer to the question regarding the feature that is unique to the sympathetic nervous system, but not the parasympathetic nervous system, is that preganglionic neurons originate in the thoracolumbar spinal cord (option E). In the sympathetic nervous system, preganglionic neurons are located in the thoracolumbar spinal cord, specifically in the lateral horn of the spinal cord from the first thoracic to the second or third lumbar segments. These preganglionic fibers release acetylcholine (ACh) at sympathetic ganglia, which then activates postganglionic neurons that release norepinephrine onto target organs. Contrastingly, the parasympathetic nervous system has preganglionic neurons that originate in the brainstem and sacral spinal cord, and its postganglionic fibers release ACh at the target organs.