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: Pediatrics
[{'content': 'In which of the following differential cyanosis found? \nSelect and explain. \nA. VSD with reversal of shunt, B. PDA with reversal of shunt, C. ASD with reversal of shunt, D. Tetralogy of Fallot', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., PDA with reversal of shunt", 'role': 'assistant'}]