Boundaries of Koch's triangle is not formed by:

Ans. C. Limbus fossa ovalisKoch's triangle, named after the German pathologist and cardiologist Walter Karl Koch, is an anatomical area located in the superficial paraseptal endocardium of the right atrium, which its boundaries are the coronary sinus orifice, tendon of Todaro, and septal leaflet of the right atrioventricular valve. It is anatomically significant because the atrioventricular node is located at the apex of the triangle.