This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Airway, Subject name: Anaesthesia
[{'content': 'What is the usual suction time of tracheostomy tube? \nSelect and explain. \nA. 10-15 seconds, B. 45 seconds, C. 60 seconds, D. 30 seconds', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Minimal time should be taken for suctioning to minimize the time period of ventilator disconnect . 10 secs is enough time for suctioning.', 'role': 'assistant'}]