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: Surgery
[{'content': 'Radiograph of mandibular 3rd molar shows fading of trabeculations and narrowing of canal in apical\nregion of tooth. What will be the diagnosis? \nSelect and explain. \nA. Deep grooving of the root and loss of dense cortical walls of the canal, B. Nerve is passing in between the roots, C. Horizontal superimposition of radiograph, D. Inherent faulty radiographic technique', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]