This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skin lesions and disorders of pigmentation, Subject name: Dental
Rain drop pigmentation is seen in 
Select and explain. 
A. Chronic lead poisoning, B. Chronic Arsenic poisoning, C. Chronic Mercury poisoning, D. All of the above
B: Chronic Arsenic poisoning
Answer: B: Chronic Arsenic poisoning 
Explanation: chronic arsenic exposure from occupations for polonged periods 1-20 years may develop diffuse pigmentation predominant over trunk and is superimposed by 2-10mm macules of depigmentation producing characteristic rain drop appearence. IADVL textbook of dermatology, disorders of pigmentation page 786