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
Rogue is used to 
Select and explain. 
A. Prevent flow of solder to unwanted areas, B. Covers the metal surface and prevents access to oxygen so that no oxide can form, C. Reduces any oxides present and exposes clean metal., D. Dissolves any oxides present and carries them a)	away.
A: Prevent flow of solder to unwanted areas
Answer: A: Prevent flow of solder to unwanted areas 
Explanation: None