This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Pediatrics
[{'content': "Single hea sound (S2) is heard in: \nSelect and explain. \nA. Transposition of great vessels, B. Ebstein's anomaly, C. Tetralogy of Fallot, D. TAPVC", 'role': 'user'}, {'content': 'Answer: C \nExplanation: --> Single second hea sound: It is either A2 / P2/ combination of both. Decision whether it is aoic / pulmonic / combination depends on location, intensity of S2 & clinical profile of pt Seen in: *Tetralogy of fallot --> S2 represents A2 component since pulmonic component is delayed, soft & inaudible. *Eisenmenger complex --> S2 represents combination of A2 & P2 - Thus, based on auscultation alone, it might be difficult to differentiate b/w TOF & Eisenmenger complex. History & chest X-ray can distinguish these conditions.', 'role': 'assistant'}]