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: Pediatrics
Widely split S1 is heard in 
Select and explain. 
A. Right bundle branch block (RBBB), B. Mitral regurgitation (MR), C. Atrial septal defect (ASD), D. Ventricular septal defect (VSD)
C: Atrial septal defect (ASD)
Answer: C: Atrial septal defect (ASD) 
Explanation: In ASD there Will be widely fixed split S2. Ref : Ghai essential of pediatrics, eighth edition, p.no:413