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': 'A routine periapical radiograph of an upper central incisor is taken by the technician. A periapical radiolucency is observed in relation to 11. Although, there is no carious lesion involvement seen clinically and the patient also does not give history of any incidence of pain or discomfort in relation to this tooth. The most probable diagnosis is: \nSelect and explain. \nA. Periapical granuloma, B. Periapical abscess, C. Incisive foramen moved by parallax over apex of the 11, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The incisive foramen\xa0varies markedly in its radiographic shape, size, and sharpness. It\xa0may appear smoothly symmetric, with numerous forms, or very\xa0irregular, with a well-demarcated or ill-defined border. The position\xa0of the foramen is also variable and may be recognized at the apices\xa0of\xa0the\xa0central\xa0incisor roots,\xa0near\xa0the alveolar crest, anywhere in\xa0between, or extending over the entire distance. The great variability\xa0of its radiographic image is primarily the result of,\n\nThe differing\xa0angles at which the X-ray beam is directed for the maxillary central\xa0incisors.\nSome variability in its anatomic size.\n\nRef: White and Pharoah, pg-138', 'role': 'assistant'}]