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
The 'Key hole' pattern appearance in the cross section is feature of 
Select and explain. 
A. Aprismatic enamel, B. Prismatic enamel, C. Intertubular dentin, D. Intratubular dentin
B: Prismatic enamel
Answer: B: Prismatic enamel 
Explanation: None