This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Introduction to Radiology, Subject name: Radiology
[{'content': 'The effective dose of a Chest x-ray is ____________. \nSelect and explain. \nA. 0.02 mSv, B. 0.2 mSv, C. 0.05 mSv, D. 0.1 mSv', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The effective dose of a CXR is 0.02 mSv. Radiation dose of a chest CT (8mSv)is 400 times more than a chest X-ray. TYPICAL EFFECTIVE DOSES Investigation Dose (mSv) PA view CXR 0.02 Skull AP/Lat 0.06 AP pelvis 0.7 AXR 0.7 Lumbar spine 1 CT brain 2 IVU 2.5 Barium meal 3 Bone scan 3 Barium enema 7 CT abdomen 10 Thallium scan 20', 'role': 'assistant'}]