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
Which of the following is function of fluoride flux in soldering process? 
Select and explain. 
A. It prevents the formation of copper oxide, B. It prevents the formation of chromium oxide or dissolves chromic oxide layer, C. It prevents the flow of material in undesirable area, D. Increases the strength of solder
B: It prevents the formation of chromium oxide or dissolves chromic oxide layer
Answer: B: It prevents the formation of chromium oxide or dissolves chromic oxide layer 
Explanation: None