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
Dustless alginate is produced by 
Select and explain. 
A. Reducing the diatomaceous earth, B. Adding heavy metal salts, C. Coating with dihydric alcohol, D. Altering the matrix
C: Coating with dihydric alcohol
Answer: C: Coating with dihydric alcohol 
Explanation: None