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': "Accessory canals result from \nSelect and explain. \nA. Defects in cementogenesis, B. Dividing epithelial bridges, C. Break in Hertwig's root sheath, D. Adherent epithelial rests", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Accessory canals may occur either due to loss of root sheath cells or due to inclusion of blood vessels during root development.', 'role': 'assistant'}]