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
Ideal pulpal depth for amalgam restoration in a primary molar is 
Select and explain. 
A. 0.5 mm from DEJ, B. 1 mm from enamel surface, C. 1.5 mm from DEJ, D. 3.2 mm from enamel surface
A: 0.5 mm from DEJ
Answer: A: 0.5 mm from DEJ 
Explanation: None