This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fundamentals in Radiology, Subject name: Radiology
Grid is a device used for - 
Select and explain. 
A. Reducing scattered radiation, B. Reducing patient's exposure time, C. Reducing the contrast of the X-ray, D. All of the above
A: Reducing scattered radiation
Answer: A: Reducing scattered radiation 
Explanation: X ray grid ensures the contrast of image on X ray film. X ray grid absorbs the scattered xrays and filters out radiations