Explanation:

- Option 1: Tuberculosis

- This is an infectious disease caused by bacteria called *Mycobacterium tuberculosis*.

- It mainly affects the lungs, but can spread to other parts of the body.

- It spreads from person to person through the air.

- Option 2: Dementia

- This is not an infectious disease.

- Dementia is a group of symptoms affecting memory and thinking, usually due to brain diseases like Alzheimer's.

- Option 3: Pulmonary hypertension

- This is a condition of high blood pressure in the vessels that supply the lungs.

- It is not caused by an infection.

- Option 4: Diabetes

- Diabetes is a chronic condition that affects how the body processes blood sugar.

- It is not an infectious disease.