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': 'Reversal of lead foil on X-ray film may appear as: \nSelect and explain. \nA. Herring bone, B. Embossed tram track pattern, C. Both 1 and 2, D. None', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Reversal of lead foil on X-ray film: Herring bone / Embossed tram track pattern.', 'role': 'assistant'}]