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
Which of follow is a non ionic contrast agent ? 
Select and explain. 
A. Ioxoglate, B. Iohexol, C. Iothalamate, D. Amidotrizoate
B: Iohexol
Answer: B: Iohexol 
Explanation: Ioxoglate is ionic dimer contrast agent Iohexol is non ionic monomer contrast agent Iothalamate and Amidotrizoate are ionic monomer contrast agents Also remember : Iodixanol and iotrolan are non ionic dimer contrast agents