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
Most common cause of the poor film radiograph 
Select and explain. 
A. Poor processing in the darkroom, B. Poor exposure, C. Poor Temperature and safe light, D. All of the above
A: Poor processing in the darkroom
Answer: A: Poor processing in the darkroom 
Explanation: At the beginning of each work day, check the levels of the processing solutions and replenish with fresh developing solution and fresh fixing solution, as necessary. The most common cause of poor film radiographs is poor processing in the darkroom, in particular, the use of depleted solutions.