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: Radiology
Restrains development of unexposed silver halide crystals; acts as antifog agents and increases contrast: 
Select and explain. 
A. Phenidone, B. Sodium hydroxide, C. Bromine containing compound, D. Sodium sulphite
C: Bromine containing compound
Answer: C: Bromine containing compound 
Explanation: None