This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'Largest opening in the Right atrium \nSelect and explain. \nA. Superior Venacava, B. Inferior Venacava, C. Right Atrioventricular Orfice, D. Coronary SInus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Right Atrioventricular Orifice Blood passes out of the right atrium through the right atrioventricular or tricuspid orifice and goes to the right ventricle. The tricuspid orifice is guarded by the tricuspid valve which maintains unidirectional flow of bloodReference: Vishram Singh Anatomy; 2nd edition; Page no: 265', 'role': 'assistant'}]