**Core Concept**
Measles is a highly contagious viral infection caused by the measles virus, characterized by fever, cough, runny nose, and a characteristic rash. The measles virus primarily affects the respiratory system, leading to inflammation of the upper respiratory tract and potentially resulting in complications such as pneumonia or encephalitis.

**Why the Correct Answer is Right**
The measles virus is a single-stranded RNA virus belonging to the paramyxoviridae family. It replicates in the respiratory epithelium, causing the characteristic symptoms of measles. The virus is highly contagious and spreads through respiratory droplets or contact with contaminated surfaces.

**Why Each Wrong Option is Incorrect**
**Option A:** Measles is caused by a DNA virus. Incorrect, as measles is caused by a single-stranded RNA virus.
**Option B:** Measles is a zoonotic disease. Incorrect, as measles is primarily a human disease with no known animal reservoir.
**Option C:** The measles vaccine is a live attenuated vaccine. Correct, but this is the correct option, so we'll move on.
**Option D:** Measles is not a vaccine-preventable disease. Incorrect, as widespread vaccination has led to a significant reduction in measles cases.

**Clinical Pearl / High-Yield Fact**
It's essential to note that measles can lead to complications such as pneumonia, encephalitis, and even death, particularly in malnourished or immunocompromised individuals.

**Correct Answer:** .