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: Physiology
Different organs receive different amounts of cardiac output. The organ with MAXIMUM blood flow in ml/kg/min is: 
Select and explain. 
A. Kidney, B. Liver, C. Brain, D. Lung
A: Kidney
Answer: A: Kidney 
Explanation: The kidneys receive 20-25% of the cardiac output. They receive the highest blood flow per gram of organ weight in the body i.e, 400 mL/min/ 100 gm. This is several times greater per unit weight of organ than the blood flow through most other organs. Ref: Radiological Imaging of the Kidney edited by Emilio Quaia, 2011, Page 24.