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
Dull appearance of mouth temperature wax indicates 
Select and explain. 
A. Insufficient material, B. Overextension, C. Contact of the material with tissues, D. Partial contact of tissues
D: Partial contact of tissues
Answer: D: Partial contact of tissues 
Explanation: None