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': "Solitary hypoechoic lesion of the liver without septae or debris is most likely to be: \nSelect and explain. \nA. Hydatid cyst, B. Caroli's disease, C. Liver abscess, D. Simple cyst", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Simple cyst', 'role': 'assistant'}]