**Core Concept**
Broncho-pneumonia refers to a type of pneumonia characterized by an acute inflammatory process involving the bronchioles and alveoli, often caused by viral or bacterial pathogens. In infants, broncho-pneumonia can be caused by various viral agents, which trigger an immune response, leading to inflammation and lung consolidation.

**Why the Correct Answer is Right**
The correct answer is **Adenovirus**, which is a common cause of viral broncho-pneumonia in infants. Adenovirus infects the respiratory tract and triggers an immune response, resulting in inflammation and consolidation of lung tissue. Other viral agents like Respiratory Syncytial Virus (RSV), Human Metapneumovirus (HMPV), and Influenza Virus are also known to cause broncho-pneumonia in infants.

**Why Each Wrong Option is Incorrect**
**Option A:** RSV is a common cause of broncho-pneumonia in infants, especially during the winter months. It infects the respiratory epithelium, leading to inflammation and consolidation of lung tissue.
**Option B:** HMPV is another viral agent that can cause broncho-pneumonia in infants, particularly in the winter and spring seasons. It infects the respiratory epithelium, triggering an immune response and inflammation.
**Option C:** Influenza Virus can also cause broncho-pneumonia in infants, especially in combination with other viral or bacterial pathogens. It infects the respiratory epithelium, leading to inflammation and consolidation of lung tissue.

**Clinical Pearl / High-Yield Fact**
In infants, viral broncho-pneumonia is often caused by a combination of viral pathogens, and a thorough diagnostic workup is essential to identify the underlying cause.

**Correct Answer:** A. Adenovirus.