This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CVS Embryology, Subject name: Anatomy
[{'content': 'Tendon of Todaro connects \nSelect and explain. \nA. Coronary sinus to tricuspid valve annulus, B. Ridge of muscle connecting IVC and SVC, C. Valve in opening of IVC, D. Raised interatrial ridge', 'role': 'user'}, {'content': "Answer: A \nExplanation: Tendon of Todaro is a pa of Koch's triangle Base: ostium of coronary sinus Superior boundary: tendon of Todaro connects central fibrous body. Inferior boundary: septal cusp of tricuspid value. Apex: bundle of his & AV node.", 'role': 'assistant'}]