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
Which of the following gene mutation occurs in cleidocranial dysplasia: 
Select and explain. 
A. CDFA1 gene., B. CBFA1 gene., C. CBFA2 gene., D. None.
B: CBFA1 gene.
Answer: B: CBFA1 gene. 
Explanation: None