This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: ENT
[{'content': 'Palpatory thud audible slap is seen in: \nSelect and explain. \nA. Tracheal foreign body, B. Bronchial foregion body, C. Laryngeal foreign body, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A foreign body in trachea may move up and down the trachea between the carnia and the undersurface of vocal cords causing "audible slap" and "palpatory thud."', 'role': 'assistant'}]