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
Polymerisation of heat-cured methyl methacrylate is initiated by: 
Select and explain. 
A. Tertiary amine, B. Benzoyl peroxide free radical, C. Hydroquinone, D. Methyl ether
B: Benzoyl peroxide free radical
Answer: B: Benzoyl peroxide free radical 
Explanation: None