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': 'The symmetrical radiopacities marked with arrow are most likely: \nSelect and explain. \nA. Genial tubercle, B. Mental ridges, C. Mylohyoid ridges, D. Both 1 and 2', 'role': 'user'}, {'content': 'Answer: B \nExplanation: On periapical radiographs of the mandibular central incisors, the\xa0mental ridge (protuberance) may occasionally be seen as two radiopaque lines sweeping bilaterally forward and upward toward the\xa0midline. They are of variable width and density and may\xa0be found to extend from low in the premolar area on each side up\xa0to the midline, where they lie just inferior to or are superimposed\xa0on the mandibular incisor roots. The image of the mental\xa0ridge is most prominent when the beam is directed parallel with\xa0the\xa0surface of the mental\xa0tubercle\xa0(as when using the bisecting-angle technique).\nRef: White and Pharoah, pg- 145', 'role': 'assistant'}]