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: Anatomy
[{'content': 'Boundary of the Kochs triangle is not formed by: \nSelect and explain. \nA. Tricuspid valve ring, B. Coronary sinus, C. Tendon of todaro, D. Limbus fossa ovalis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Triangle of koch is landmark for AV node with its transition zone. It is bounded by tendon of todaroQ (superiorly), tricuspid valve septal leafletQ (inferiorly) and coronary sinus orificeQ (basally)', 'role': 'assistant'}]