**Core Concept**
Measles is a viral infection caused by the measles virus, leading to a characteristic rash and symptoms. The presence of giant cells in measles is a notable histopathological feature, indicating the body's immune response to the infection.

**Why the Correct Answer is Right**
Giant cells in measles are called Warthin-Finkeldey cells. These cells are multinucleated giant cells formed by the fusion of infected cells and lymphocytes. The measles virus causes the infected cells to undergo syncytium formation, resulting in the characteristic giant cells. This process is mediated by the viral glycoprotein, which induces the fusion of cells. Warthin-Finkeldey cells are seen in the lymphoid tissues and are a hallmark of measles infection.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify the correct type of cells associated with measles.
**Option B:** This option is incorrect as it refers to a different type of cell associated with other viral infections, not measles.
**Option C:** This option is incorrect as it refers to a type of cell associated with a different disease process.

**Clinical Pearl / High-Yield Fact**
Warthin-Finkeldey cells are a classic histopathological feature of measles infection and can be seen in lymphoid tissues, such as lymph nodes and tonsils.

**Correct Answer: . Warthin-Finkeldey cells.**