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': 'Acoustic shadow in USG is due to \nSelect and explain. \nA. Aefact, B. Absorption, C. Reflection, D. Refraction', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Reflection', 'role': 'assistant'}]