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
A middle aged man presents with paraesthesia of hands and feet. Examination reveals presence of 'Mees' lines in the nails and rain drop type pigmentation in the hands. The most likely causative toxin for the above mentioned symptoms is: 
Select and explain. 
A. Lead, B. Arsenic, C. Thallium, D. Mercury
B: Arsenic
Answer: B: Arsenic 
Explanation: CNS symptoms along with 'Aldrich-Mees lines' in the nails and rain drop type pigmentation in the hands suggests this case as chronic Arsenic poisoning. Ref: The Essentials of Forensic Medicine and Toxicology By K S Narayan Reddy, 27th Edition, Pages 473,475,476,478,482