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
Crown infarction is 
Select and explain. 
A. Necrosis of pulp following a fracture, B. An incomplete fracture of enamel without loss of tooth structure, C. Fracture of crown en mass, D. Vertical fracture of crown
B: An incomplete fracture of enamel without loss of tooth structure
Answer: B: An incomplete fracture of enamel without loss of tooth structure 
Explanation: None