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
Discoloration of a denture constructed from cold cure acrylic resin is due to: 
Select and explain. 
A. Absorption of oral fluids, B. PH changes in saliva, C. Leaching out of tertiary amines, D. Leaching out of excess monomer
C: Leaching out of tertiary amines
Answer: C: Leaching out of tertiary amines 
Explanation: None