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
Triangle of Koch is not formed by 
Select and explain. 
A. Limbus of Fossa ovalis, B. Tendon of Todaro, C. Coronary sinus, D. Septal Cusp of Tricuspid valve
A: Limbus of Fossa ovalis
Answer: A: Limbus of Fossa ovalis 
Explanation: Triangle of Koch is formed by

Tendon of Todaro
Coronary sinus
Septal Cusp of Tricuspid valve