Common cold differs from pneumonia as

Options

A. Pneumonia is caused by a virus whereas common cold is caused by a bacterium
B. pneumonia pathogen infects alveoli whereas common cold affects nose and respiratory passage but not the lungs
C. pneumonia is a non-communicable disease whereas common cold is a communicable disease
D. none of these

Explanation

### Step-by-Step Solution:

1. **Identify the Diseases**: Understand that the two diseases in question are common cold and pneumonia.

2. **Causes of the Diseases**:
- Common cold is primarily caused by a virus, most commonly the rhinovirus.
- Pneumonia is caused by bacteria, with the most common being **Haemophilus influenzae** and **Streptococcus pneumoniae**.

3. **Infection Sites**:
- Pneumonia primarily affects the lungs, specifically the alveoli (the small air sacs in the lungs).
- Common cold affects the upper respiratory tract, particularly the nose and respiratory passages, but does not typically involve the lungs.

4. **Communicability**:
- Both common cold and pneumonia are communicable diseases, meaning they can be transmitted from one person to another.
- The statement claiming pneumonia is a non-communicable disease is incorrect.

5. **Evaluate the Statements**:
- The first statement is incorrect because it misidentifies the causes of the diseases.
- The second statement is correct as it accurately describes the infection sites of both diseases.
- The third statement is incorrect because it misclassifies pneumonia as a non-communicable disease.

6. **Conclusion**: The correct answer is that common cold differs from pneumonia in that pneumonia infects the alveoli while common cold affects the nose and respiratory passages.

### Final Answer:
The correct option is **B**: Pneumonia pathogen infects alveoli whereas common cold affects nose and respiratory passage but not the lungs.

---