This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiac and Pericardiac Imaging, Subject name: Radiology
[{'content': 'Which among the following is NOT a cause of calcification in anterior mediastinal mass? \nSelect and explain. \nA. Lymphoma after radiotherapy, B. Aneurysm of ascending aorta, C. Germ cell tumor, D. Leiomyoma of esophagus', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans: D Posterior mediastinum contents Mnemonic: DATES -- Descending aorta. Azygous vein and hemiazygos vein, Thoracic duct, Esophagus, Sympathetic trunk/ganglia.', 'role': 'assistant'}]