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: Forensic Medicine
Sex can be established by examining hair root cells for the presence of: 
Select and explain. 
A. Davidson body, B. Barr body, C. Golgi body, D. Medullary index
B: Barr body
Answer: B: Barr body 
Explanation: Barr body