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
Passivating alloys are: 
Select and explain. 
A. Cr, Al, Ti, B. Cr, Mo, Ti, C. Cr, Gold, Ti, D. Cr, Fe, Ti
A: Cr, Al, Ti
Answer: A: Cr, Al, Ti 
Explanation: None