Final answer:
The aorta cuts through the diaphragm at T12, marking the transition point from the thoracic aorta to the abdominal aorta.
Step-by-step explanation:
The aorta crosses through the diaphragm at the aortic hiatus. This event is significant because it marks the transition of the aorta from the thoracic aorta to the abdominal aorta. According to the anatomical details provided, the thoracic aorta commences at the level of vertebra T5 and extends through the diaphragm at the level of T12. Therefore, the correct answer to the question, "Aorta cuts through Diaphragm at ___," is C. T12.
The aortic hiatus is an opening in the diaphragm located at the level of the twelfth thoracic vertebra (T12). The thoracic vertebrae are numbered from T1 (at the top) to T12 (at the bottom) and are part of the spine in the thoracic or chest region.