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: Surgery
All of the following methods are used for detecting heavy metals, EXCEPT: 
Select and explain. 
A. Harrison & Gilroy test, B. . Paraffin test, C. Neutron activation analysis, D. Atomic adsorption spectroscopy
B: . Paraffin test
Answer: B: . Paraffin test 
Explanation: All the others except Paraffin test are used to detect heavy metals. These heavy metals are detected from the entrance wound where they are components of the residue discharged from the caridge of a firearm weapon. Harrison & Gilroy Test- Sb, Ba, Pb, in firearm discharges. N.A.A. - radioisotopes, A.A.S.- Sb, Ba, Cu. Paraffin test=Dermal Nitrate test=Diphenylamine test- detects Nitrates/Nitrites from a cast of paraffin on the hands, not heavy metals.