The "dorsal columns" refer to the? A. Axonal bundies of neurons in dorsal column nuclei running from medulla to thalamus B. Peripheral processes of sensory afferent fibers of dorsal root ganglion neurons C. Axonal bundies of dorsal root ganglion neurons running in the dorsal aspect of the spinal cord D. Gray-matter columns on the dorsal side of the spinal cord E. Avonal bundles of spinal dorsal horn neurons running in the spinal cord.