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': "Pseudokidney sign' on USG is seen in \nSelect and explain. \nA. Trichobezoar, B. CA stomach, C. CA kidney, D. Polycystic kidney", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. CA stomach', 'role': 'assistant'}]