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: Pathology
Thistle-tube appearance of pulp chamber is a feature of: 
Select and explain. 
A. Coronal dentin dysplasia, B. Regional odontodysplasia, C. Dentinogenesis imperfecta, D. Amelogenesis imperfecta
A: Coronal dentin dysplasia
Answer: A: Coronal dentin dysplasia 
Explanation: None