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': 'Which of the following interactions does not cause film fog? \nSelect and explain. \nA. Coherent scattering, B. Transient scattering, C. Photoelectric absorption, D. Compton scattering', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]