**Core Concept**
Polycystic Ovary Syndrome (PCOS) is characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology on ultrasound. The ultrasound findings in PCOS typically include an increased ovarian volume, presence of multiple small follicles, and thickened ovarian stroma. These findings are often accompanied by hyperandrogenism and ovulatory dysfunction.

**Why the Correct Answer is Right**
Option B is incorrect because a normal ovarian volume is typically defined as less than 10 cc in premenopausal women. In contrast, women with PCOS often have an increased ovarian volume, which can be greater than 10 cc. This is due to the presence of multiple small follicles and thickened ovarian stroma, which can lead to an enlarged ovary. The ovarian volume is a key ultrasound finding in PCOS, and an ovarian volume less than or equal to 10 cc is not consistent with the diagnosis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is actually a characteristic ultrasound finding in PCOS, as the presence of multiple small follicles (typically greater than 20) is a key criterion for diagnosing PCOS. These follicles are usually less than 9 mm in size and are often referred to as "small follicles" or "stippled appearance".

**Option C:** The "necklace of pearl" pattern of follicles is a characteristic ultrasound finding in PCOS, resulting from the presence of multiple small follicles in a linear array. This pattern is often seen in women with PCOS and is a key criterion for diagnosing the condition.

**Option D:** Thickened ovarian stroma is a characteristic ultrasound finding in PCOS, often resulting in an increased ovarian volume. The stroma appears echogenic or hyperechoic on ultrasound, which can be distinguished from the surrounding follicles.

**Clinical Pearl / High-Yield Fact**
When evaluating a woman for PCOS, it's essential to look for the characteristic ultrasound findings, including an increased ovarian volume, multiple small follicles, and thickened ovarian stroma. These findings, combined with hyperandrogenism and ovulatory dysfunction, are key criteria for diagnosing PCOS.

**✓ Correct Answer: B. Ovarian Volume <=10 cc**