Final answer:
The aorta passes through the aortic hiatus at T12, which is a landmark that divides the aorta into the superior thoracic and inferior abdominal components.
Step-by-step explanation:
The aorta passes through the aortic hiatus at T12, which is a landmark that divides the aorta into the superior thoracic and inferior abdominal components. The aortic hiatus is an opening in the diaphragm which allows the aorta to continue its descent into the abdominal region, where it is called the abdominal aorta. Therefore, the correct answer is D. Thoracic duct.