## **Core Concept**
The Varicella zoster virus (VZV) is a member of the herpesvirus family, which is known for causing infections that can lead to latent infections. VZV causes chickenpox (varicella) primarily in children and can reactivate later in life to cause shingles (herpes zoster). The latent phase of the virus is crucial for its lifecycle, allowing it to remain dormant within the host.

## **Why the Correct Answer is Right**
The correct answer, **D. Dorsal root ganglion**, is right because Varicella zoster virus becomes latent in the **dorsal root ganglia** of the sensory nerves. After a person recovers from chickenpox, the virus can travel to the nerve cells (neurons) and remain dormant in the dorsal root ganglia. This latency can last for years or even decades, and the virus can reactivate, typically due to waning immunity with age or immunosuppression, leading to herpes zoster or shingles.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Incorrect because while VZV initially infects the skin, leading to the rash of chickenpox, it does not remain latent in the skin cells.
- **Option B:** Incorrect as the virus does not primarily become latent in the liver; though the liver can be involved in the viremic phase of the infection.
- **Option C:** Incorrect because, although the virus does infect and replicate in the lungs, the lungs are not a site of latency for VZV.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the reactivation of latent Varicella zoster virus, leading to shingles, is more common in individuals over the age of 50 or those with weakened immune systems. The pain associated with shingles, known as postherpetic neuralgia (PHN), can be severe and prolonged. Early treatment with antiviral drugs can help reduce the risk of complications.

## **Correct Answer:** D. Dorsal root ganglion.