**Core Concept**
The immune response to varicella-zoster virus (VZV) infection involves the production of specific antibodies, primarily IgG and IgM, which provide long-term immunity against chickenpox. IgG antibodies are crucial for neutralizing the virus and preventing its spread.

**Why the Correct Answer is Right**
In individuals who are immune to chickenpox, the primary antibody class expected to be found is IgG. This is because IgG antibodies provide long-term immunity against VZV and are responsible for neutralizing the virus. IgG antibodies are also transferred from mother to child during pregnancy, which is why neonates born to immune mothers are usually protected against chickenpox. **IgG antibodies** are produced in response to VZV infection and persist for life, offering protection against future infections.

**Why Each Wrong Option is Incorrect**
* **Option A:** IgM antibodies are primarily involved in the early response to VZV infection and are usually detectable within 3-5 days after the onset of symptoms. They are not the primary antibody class responsible for long-term immunity.
* **Option B:** IgE antibodies are associated with allergic reactions and are not involved in the immune response to VZV.
* **Option C:** IgA antibodies are primarily found in mucosal secretions and play a role in mucosal immunity, but they are not the primary antibody class responsible for long-term immunity against VZV.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that IgG antibodies are the primary indicator of immunity against VZV, and their presence can be used to diagnose past infection or immunity. This is particularly relevant in healthcare workers, such as the college student in this scenario, who are at risk of exposure to patients with VZV.

**Correct Answer:** C. IgG.