This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Larynx, Subject name: ENT
[{'content': 'A 2 years male boy presenting with sudden severe dyspnoea, most common cause is \nSelect and explain. \nA. Foreign body, B. Bronchiolits, C. Asthmatic attack, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: For 2 years male boy presenting with sudden severe dyspnoea, the most common cause is a foreign body. Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 334', 'role': 'assistant'}]