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: Medicine
[{'content': 'In an ICU patient is on invasive monitoring, All are causes of bacterial sepsis except - \nSelect and explain. \nA. Orotracheal intubation, B. Intra arterial line, C. Humidified air, D. Central venous catheter', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]