This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
Which congenital hea disease is associated with pre excitation ? 
Select and explain. 
A. Atrial Septal Defect, B. Bicuspid Aoic Valve, C. Ebsteins Anomaly, D. Patent Ductus Aeriosus
C: Ebsteins Anomaly
Answer: C: Ebsteins Anomaly 
Explanation: ebsteins anomaly is a congenital hea condition which is associated with pre excitation Ebstein anomaly is a rare hea defect in which the tricuspid valve -- the valve between the upper right chamber (right atrium) and the lower right chamber (right ventricle) of the hea -- doesn't work properly. As a result, blood leaks back through the valve and into the right atrium. Ref Harrison 20th edition pg 1553