This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach & Duodenum, Subject name: Surgery
In congenital pyloric stenosis the defect usually lies in the antral: 
Select and explain. 
A. Nerve fibers, B. Circular muscle fibers, C. Longitudinal muscle fibers, D. Mucosa
B: Circular muscle fibers
Answer: B: Circular muscle fibers 
Explanation: Ans. (b) Circular muscle fibersRef: Bailey and Love 26th Edition, Page 113* Circular muscle hypertrophy results- hence pyloromyotomy we cut these muscles