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: Radiology
[{'content': 'Target sign on USG is seen in \nSelect and explain. \nA. Congenital hypertrophic pyloric Stenosis, B. Gastric ulcers, C. Achalasia, D. All the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Target sign - hypoechoic ring and hypertrophied pyloric muscle around echogenic mucosa\nCentrally on transverse Scan - Seen in CHPS.', 'role': 'assistant'}]