This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Radiotherapy, Subject name: Radiology
Most radiosensitive tissue of body among the following is 
Select and explain. 
A. Bone marrow, B. Spleen, C. Kidney, D. Brain
A: Bone marrow
Answer: A: Bone marrow 
Explanation: Ans. a (Bone marrow). (Ref. Harrison, Medicine, 15th ed., 2588)The minimal tolerance dose (Rads) for (TD 5/5):Bone marrow250 (radiosensitive)Spleen1000Kidney1500Brain5000 (radioresistant)Liver2500Intestine4500Heart3000Lung3000Testis600-1000 (radiosensitive)