Barium in a suitable form is administered to patients before an X-ray examination of the stomach, because

• A. Barium allows X-rays to pass through the stomach on account of its transparency to X-rays
• B. Barium compound,like magnesium sulphate helps in cleaning the stomach before X-ray examination
• C. Barium is a good absorber of X-ray and this helps the stomach to appear clearly in contrast with the other regions in the picture
• D. Barium salts are white in colour and this helps the stomach to appear clearly in contrast with other regions in the picture