This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
Most specific test to detect blood stains is 
Select and explain. 
A. Benzidine test, B. Teichmann's test, C. Ohotoluidine test, D. Spectroscopic test
D: Spectroscopic test
Answer: D: Spectroscopic test 
Explanation: Spectroscopic test is the most specific for blood stains. Tests for blood stains Spectroscopy tests can give information about what chemical compounds and elements are present in a sample, whether ceain types of degradation have occurred in a sample, the amount and type of crystallinity present in the sample, to name a few uses. Ref ganong's review of medical physiology 25e