Which condition is caused by a bacterium that primarily affects the lungs but can spread to other parts of the body?
Correct Answer: A
Rationale: The correct answer is A: Tuberculosis. Tuberculosis is caused by the bacterium Mycobacterium tuberculosis, which primarily affects the lungs but can spread to other parts of the body through the bloodstream or lymphatic system. This bacterium specifically targets the lungs, leading to symptoms such as coughing, chest pain, and difficulty breathing. In contrast, Pneumonia (B) is commonly caused by viruses, bacteria, or fungi affecting the lungs but doesn't specifically spread to other body parts like TB. Legionnaires' disease (C) is caused by Legionella bacteria and primarily affects the lungs, but it does not have the same capability to spread to other body parts like TB. Histoplasmosis (D) is a fungal infection that primarily affects the lungs but does not spread to other parts of the body in the same way as tuberculosis.