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
Yellowish-brown staining of the IOPA dental X-ray film is due to: 
Select and explain. 
A. Immersion in fixer without washing, B. Increased temperature of developer, C. Increased exposure time, D. Drying away of the developer solution
A: Immersion in fixer without washing
Answer: A: Immersion in fixer without washing 
Explanation: None