Ten-year-old Tina falls while climbing a tree and lands on her back. Her frightened parents take her to the local emergency room where she is examined. Her knee jerk reflex is normal. These results suggest that
◦ Tina has injured one of her descending nerve tracts.
◦ Tina suffered no damage to her spinal cord.
◦ Tina has a spinal injury in the lumbar region.
◦ Tina has injured one of her ascending nerve tracts.
◦ Tina has a spinal injury in the cervical region.