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: Dental
Many dentists criticized the poor quality of the early amalgam restorations and this controversy led to the “amalgam war” from – 
Select and explain. 
A. 1820  to  1830, B. 1840  to  1850, C. 1870  to  1880, D. 1880  to  1890
B: 1840  to  1850
Answer: B: 1840  to  1850 
Explanation: Many dentists criticized the poor quality of the early amalgam restorations.This controversy led to the “amalgam war” from 1840 to 1850.
Reference: Phillip’s Science of Dental Materials, Pg-8