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
The imperfection seen on the lingual flange of a lower denture caused by rapid heating during a curing cycle is called: 
Select and explain. 
A. Localised shrinkage porosity, B. Gas inclusion porosity, C. Micro-porosity, D. Surface porosity
D: Surface porosity
Answer: D: Surface porosity 
Explanation: None