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
Largest opening in the Right atrium 
Select and explain. 
A. Superior Venacava, B. Inferior Venacava, C. Right Atrioventricular Orfice, D. Coronary SInus
C: Right Atrioventricular Orfice
Answer: C: Right Atrioventricular Orfice 
Explanation: 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