**Question:** TB is associated with

A. Lungs
B. Kidneys
C. Heart
D. Skin

**Core Concept:** Tuberculosis (TB) is an infectious disease primarily caused by the bacterium Mycobacterium tuberculosis. It primarily affects the lungs but can involve other organs as well. The disease is spread through the air when an infected person coughs, sneezes, or talks, releasing the bacteria into the air where they can be inhaled by others.

**Why the Correct Answer is Right:** The correct answer is A. Lungs because TB is primarily known to affect the respiratory system. The lungs are the primary site of infection where the bacteria colonize and cause destruction of lung tissue, leading to symptoms like cough, sputum production, and chest pain. In some cases, the disease can spread to other organs, but the primary site of infection remains the lungs.

**Why Each Wrong Option is Incorrect:**

B. Kidneys (Kidney): While TB can infect the kidneys, it is not the primary site of infection. Kidney involvement is usually secondary to primary pulmonary TB.

C. Heart: Although TB can infect the heart, it is relatively rare. Heart TB is usually secondary to primary pulmonary TB.

D. Skin (Skin TB): Cutaneous tuberculosis, also known as skin TB, is a less common manifestation of TB. The disease primarily affects the lungs and, less commonly, other organs.

**Clinical Pearl:** A high index of suspicion is required to diagnose TB when it affects organs other than the lungs. Early recognition and prompt treatment are essential to prevent further spread and complications.

**Correct Answer:** A. Lungs