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': 'External manifestations of lines of Retzius which are present as transverse wave line groove are called as: \nSelect and explain. \nA. Incremental line of Von Ebner., B. Incremental line of Owen., C. Perikymata., D. Enamel cuticle.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Perikymata is the external manifestation of lines of retzius.', 'role': 'assistant'}]