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
Which of the following test are used for arsenic poisoning -a) Marsh's testb) Reinsh's test c) Macewan's test d) Marqui's test 
Select and explain. 
A. ac, B. a, C. ad, D. ab
D: ab
Answer: D: ab 
Explanation: Marsh's test and Reinsh's test were used arsenic poisoning, but are obsolete now.