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
Regarding dispersion strengthening 
Select and explain. 
A. Increasing the strength of ceramic by dispersing their matrix with the crystalline phase of the same material, B. The crystalline phase works by hindering the crack propagation, C. The strengthening is due to polymorphic transformation, D. CAD CAM procedures in these materials further decrease their surface flaws
B: The crystalline phase works by hindering the crack propagation
Answer: B: The crystalline phase works by hindering the crack propagation 
Explanation: None