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
Excessive fixing of an x-ray film: 
Select and explain. 
A. Cause brown stains, B. Reduces the density, C. Increases the density, D. No effect on density
B: Reduces the density
Answer: B: Reduces the density 
Explanation: The degree of darkening or opacity of an exposed film is referred to as optical density.
Excessive fixation causes the image to become light, thereby reducing the optical density of the X-ray film.
White and Pharoah's Oral Radiology Principles and Interpretation 8th edition