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
All of the following are true for traditional solution liner, except: 
Select and explain. 
A. It is not necessary in moderately deep cavities under glass ionomer restoration, B. Have Film thickness of 1 -50 microns, C. Do not provide thermal or electric insulation, D. Protect the pulp from reaction products leaching out of restoration
B: Have Film thickness of 1 -50 microns
Answer: B: Have Film thickness of 1 -50 microns 
Explanation: None