This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Peptic Ulcer Disease, Subject name: Medicine
[{'content': 'Investigation of choice for dysphagia lusoria is? \nSelect and explain. \nA. Barium studies, B. X-ray, C. CT angiography, D. Esophageal manometry', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Dysphagia lusoria Compression of the oesophagus by the aberrant right subclan aery * Barium study of the esophagus may show the indentation on the posterior esophageal wall by the aery. * Chest x-ray can demonstrate enlargement of the superior mediastinum. * CT angiography and MRI thorax are the best diagnostic modalities that could identify the dysphagia lusoria. * In children, the most common presentations are stridor and recurrent chest infections, may be due to their tracheal softening comparing to adult population.', 'role': 'assistant'}]