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: Anaesthesia
[{'content': 'Which of the following inhaled gas is used to decrease pulmonary artery pressure in adults and infants ? \nSelect and explain. \nA. Nitrous oxide, B. Nitrogen dioxide, C. Nitric oxide, D. Nitrogen', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Nitric oxide dilates pulmonary vessels both in infants (used in persistent primary pulmonary hypertension) as well as in adults (used in primary pulmonary hypertension).', 'role': 'assistant'}]