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
[{'content': 'Which of the following is the most radiosensitive tissue? \nSelect and explain. \nA. Brain, B. Bone marrow, C. Thyroid, D. Liver', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Tissues with highest mitotic activity are highly radiosensitive. The tissues with high radiosensitivity are lymphoid tissue, bone marrow, mucosa of the GIT and germinal tissue. Least radiosensitive tissues are: Bone (least) Brain, muscle and skin Effects of radiation in different tissues: Hematopoietic system: Lymphopenia Thrombocytopenia Bone marrow hypoplasia Vascular system: Thrombosis Ischemic damage Integumentary system Acutely: erythema, edema, blistering Chronic: potential for squamous cell carcinoma Cancers caused by radiation: Acute leukemia Papillary carcinoma Osteogenic carcinoma Ref: Rapid Review Pathology By Edward F. Goljan page 173.', 'role': 'assistant'}]