**Core Concept**
Hilar lymphadenopathy, a sign of mediastinal involvement, is a characteristic feature of classical Hodgkin's lymphoma, particularly the nodular sclerosis subtype. This condition results from the accumulation of Reed-Sternberg cells and their variants in the lymph nodes.

**Why the Correct Answer is Right**
Nodular sclerosis Hodgkin's lymphoma (NSHL) is characterized by the presence of a collagenous band (referred to as the "sclerosis") within the lymph node, which separates the nodules of affected lymphocytes. The hilar lymphadenopathy observed in NSHL is due to the involvement of the mediastinal lymph nodes by Reed-Sternberg cells, which are a hallmark of this disease. The correct subtype of Hodgkin's disease, which is associated with hilar lymphadenopathy, is nodular sclerosis Hodgkin's lymphoma.

**Why Each Wrong Option is Incorrect**
**Option A:** Lymphocyte-predominant Hodgkin's lymphoma (LPHL) is a subtype of Hodgkin's lymphoma characterized by the presence of lymphocytic and histiocytic (L&H) cells, also known as "popcorn cells." This subtype does not typically present with hilar lymphadenopathy.

**Option B:** Mixed cellularity Hodgkin's lymphoma (MCHL) is another subtype of Hodgkin's lymphoma, characterized by a mixture of different types of immune cells, including lymphocytes, histiocytes, and Reed-Sternberg cells. While MCHL can present with lymphadenopathy, it is not typically associated with hilar lymphadenopathy.

**Option C:** Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare subtype of Hodgkin's lymphoma characterized by the presence of lymphocytic and histiocytic (L&H) cells, also known as "popcorn cells." This subtype does not typically present with hilar lymphadenopathy.

**Clinical Pearl / High-Yield Fact**
It is essential to recognize the characteristic radiographic features of nodular sclerosis Hodgkin's lymphoma, including the presence of a mediastinal mass and hilar lymphadenopathy, as this can aid in the diagnosis of this condition.

**Correct Answer:** C. Nodular sclerosis Hodgkin's lymphoma.