**Core Concept**
Sex cord stromal tumors are a group of rare, malignant ovarian tumors that arise from the sex cords and stroma of the ovary. These tumors are characterized by their heterogeneous nature and can be classified into several subtypes, including granulosa cell tumors, Sertoli-Leydig cell tumors, and sex cord tumors with annular tubules.

**Why the Correct Answer is Right**
Sex cord stromal tumors are typically composed of cells that produce hormones, leading to various clinical manifestations. Granulosa cell tumors, for example, secrete estrogen, which can cause endometrial hyperplasia and other symptoms. Sertoli-Leydig cell tumors can produce androgens, resulting in virilization. The correct answer to this question will exclude one of these tumor types.

**Why Each Wrong Option is Incorrect**
**Option A:** Granulosa cell tumors are a type of sex cord stromal tumor, characterized by their production of estrogen and potential to cause endometrial hyperplasia. Incorrect because it is a correct example of a sex cord stromal tumor.
**Option B:** Sertoli-Leydig cell tumors are another subtype of sex cord stromal tumor, which can produce androgens and cause virilization. Incorrect because it is a correct example of a sex cord stromal tumor.
**Option C:** Sex cord tumors with annular tubules are a rare subtype of sex cord stromal tumor, often associated with Peutz-Jeghers syndrome. Incorrect because it is a correct example of a sex cord stromal tumor.

**Clinical Pearl / High-Yield Fact**
Sex cord stromal tumors are often diagnosed incidentally during imaging studies for other pelvic pathologies. A high index of suspicion and awareness of these rare tumors is essential for accurate diagnosis and treatment.

**Correct Answer:** D.