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: Dental
[{'content': 'Most common area where prism-less or structure-less enamel is found: \nSelect and explain. \nA. Cervical area., B. Cusp tip., C. Incisal edge., D. All of the above.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Most common area where prism less or structure less enamel found – Cervical area.\nLeast common area where prism less or structure less enamel found – Cusp tip.', 'role': 'assistant'}]