This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pediatrics
[{'content': "A 2 month old child, born prematurely is brought with respiratory distress. Cardiac examination revealed increased pulse peessure and a pansystolic murmur best heard in 2nd left intercostal space. The most probable diagnosis would be \nSelect and explain. \nA. Atrial septal defect, B. Ventricular septal defect, C. Patent ductus aeriosus, D. Tetralogy of fallot's", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Patent ductus aeriosus (PDA) is a persistent opening between the two major blood vessels leading from the hea. The opening, called the ductus aeriosus, is a normal pa of a baby&;s circulatory system before bih that usually closes sholy after bih. Reference: GHAI Essential pediatrics, 8th edition', 'role': 'assistant'}]