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
ABO antigens is not found in: AIIMS 09; NEET 14 
Select and explain. 
A. CSF, B. Semen, C. Sweat, D. Saliva
A: CSF
Answer: A: CSF 
Explanation: Ans. CSF