**Core Concept**
Call-Exner bodies are a characteristic histopathological feature of certain types of ovarian tumors, specifically granulosa cell tumors. They are small, rounded or ovoid structures composed of a central space surrounded by a rosette of granulosa cells.

**Why the Correct Answer is Right**
Call-Exner bodies are formed due to the accumulation of granulosa cells around a central space, which may contain eosinophilic material. This unique cellular arrangement is a result of the proliferative and secretory activity of granulosa cells. The presence of Call-Exner bodies is a key diagnostic feature of granulosa cell tumors, helping pathologists to differentiate them from other types of ovarian tumors.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the question as Call-Exner bodies are not associated with this type of tumor.
**Option B:** This option is incorrect as Call-Exner bodies are not a feature of Brenner tumors, which have a different histopathological appearance.
**Option C:** This option is incorrect as Call-Exner bodies are not a characteristic of mucinous cystadenomas, which have a distinct histological appearance.

**Clinical Pearl / High-Yield Fact**
The presence of Call-Exner bodies is a key diagnostic feature of granulosa cell tumors, which can be challenging to distinguish from other types of ovarian tumors. Therefore, pathologists should carefully examine the histological slides for the presence of these characteristic structures.

**Correct Answer: C. Granulosa cell tumors**