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
[{'content': 'Reactivation tuberculosis is almost excusively a disease of the - \nSelect and explain. \nA. Lungs, B. Bones, C. Joints, D. Brain', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Secondary TB is due to reactivation and involves Lung particularly the apical and posterior segments of upper lobe.', 'role': 'assistant'}]