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
Hemifacial microsomia occurs during: 
Select and explain. 
A. Formation of germ layer, B. Migration of neural crest cells, C. At the time of organ formation, D. Final differentiation of tissue
B: Migration of neural crest cells
Answer: B: Migration of neural crest cells 
Explanation: None