Final answer:
Mary has a fracture of the first lumbar vertebra, known as the L1 vertebra. This is a significant injury located in the lower back part of the spinal column, which can affect her mobility and sensation.
Step-by-step explanation:
Mary has suffered a fracture to her L1 area, which refers to the first lumbar vertebra. The human spinal column consists of several regions, with the lumbar region located in the lower back. Specifically, it incorporates five vertebrae labeled as L1-L5. A fracture in this region, particularly the L1 vertebra, can cause significant pain and mobility issues due to its role in supporting the upper body's weight and allowing for movement.
Trauma to the vertebral column, such as that sustained in a car accident, can have serious repercussions, including compression and hemisection of the spinal column. These injuries can lead to paralysis and loss of sensation, depending on the severity and location of the damage.
Therefore, Mary's injury, a fracture of the first lumbar vertebra, is correctly identified as option A. It is a specific injury to a single vertebra and does not refer to the entire lumbar area, the thoracic area, the eye socket, or the sacral area.