Bilateral ovarian cancer with capsule breached ascites positive for malignant cells, Stage is:

**Core Concept**
The question requires the application of the FIGO (International Federation of Gynecology and Obstetrics) staging system for ovarian cancer, specifically to determine the stage based on the presence of ascites and malignant cells, and the breach of the ovarian capsule.

**Why the Correct Answer is Right**
The FIGO staging system for ovarian cancer is based on the extent of tumor spread. For stage III, the tumor involves one or both ovaries, with tumor on the surface of the liver or spleen, or metastases to the peritoneum outside the pelvis, or positive regional lymph nodes, or distant metastasis. In this case, the presence of bilateral ovarian cancer with a breached capsule and ascites positive for malignant cells indicates that the cancer has spread beyond the ovaries, meeting the criteria for stage III. Specifically, the involvement of the peritoneal cavity with malignant cells is a hallmark of stage III disease.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the information provided does not indicate that the cancer is limited to the ovaries (stage I).
**Option B:** This option is incorrect because the cancer has spread beyond the ovaries, which is not consistent with stage II disease.
**Option C:** This option is incorrect because the cancer has breached the ovarian capsule and is present in the ascites, which is not consistent with stage I disease.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the FIGO staging system is based on surgical findings at the time of diagnosis, and the stage may change post-operatively based on the pathologic examination of the tumor and any metastatic sites.

**Correct Answer: C. Stage III**