Final answer:
The correct answer to the question is 'a) Spinal cord; thalamus,' as inbound somatosensory information from the body is routed through ascending pathways in the spinal cord to the thalamus before reaching the cerebral cortex.
Step-by-step explanation:
Incoming somatosensory signals pass from the spinal cord through ascending pathways and are then transmitted to the thalamus. The thalamus is a critical structure that functions as a relay station, channeling sensory information to the cerebral cortex for processing.
It filters and processes sensory signals, except for the sense of smell. Sensory information from below the neck travels via the spinal cord, while somatosensory information from the head and neck region is transmitted through the cranial nerves, particularly the trigeminal system. Therefore, the correct answer is a) Spinal cord; thalamus.