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
Which of the following statements about the contrast in radiography is true – 
Select and explain. 
A. Ionic monomers have three iodine atoms per two particles in solution, B. Osmolar contrast agents may be ionic or non ionic, C. Gadolinum may cross the blood brain barrier, D. Iohexol is a high osmolar contrast media
A: Ionic monomers have three iodine atoms per two particles in solution
Answer: A: Ionic monomers have three iodine atoms per two particles in solution 
Explanation: None