**Core Concept**
Hodgkin's lymphoma is a type of lymphoma characterized by the presence of Reed-Sternberg cells, which is a distinct morphological feature. The disease often presents with lymphadenopathy, which is the enlargement of lymph nodes.

**Why the Correct Answer is Right**
In Hodgkin's lymphoma, the lymph nodes are typically involved in a specific pattern, with the most common site being the cervical lymph nodes. This is due to the fact that the disease often starts in the lymphoid tissues of the neck, such as the lymph nodes in the jugular chain. The involvement of the cervical lymph nodes is a hallmark of Hodgkin's lymphoma, and it is often the first site of presentation.

**Why Each Wrong Option is Incorrect**
**Option A:** The axillary lymph nodes are not the most common site of enlargement in Hodgkin's lymphoma, although they can be involved in advanced disease.
**Option B:** The inguinal lymph nodes are not typically involved in Hodgkin's lymphoma, except in cases where the disease has spread to the pelvic region.
**Option C:** The mediastinal lymph nodes can be involved in Hodgkin's lymphoma, particularly in the context of mediastinal masses, but they are not the most common site of enlargement.

**Clinical Pearl / High-Yield Fact**
In Hodgkin's lymphoma, the presence of Reed-Sternberg cells is a diagnostic hallmark, and the disease often presents with painless lymphadenopathy. It is essential to consider Hodgkin's lymphoma in the differential diagnosis of lymphadenopathy, particularly in young adults.

**Correct Answer:** C.