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: Pathology
The most radiosensitive tissue is - 
Select and explain. 
A. Brain, B. Bone marrow, C. Thyroid, D. Liver
B: Bone marrow
Answer: B: Bone marrow 
Explanation: Radiosensitivity of important organs in decreasing order.
Bone marrow > Testes > Ovary > Kidney > Liver > Lung > Heart > GIT (Stomach > Intestine) > Thyroid > Brain & spinal cord (CNS) > Skin + Cartilage > Adult bone > Vagina > Uterus.