**Core Concept**
Serous cystadenocarcinoma is a type of epithelial ovarian cancer, which is often diagnosed at an advanced stage with metastasis to surrounding tissues, including the omentum. The standard surgical approach for ovarian cancer involves a complete surgical staging procedure to assess the extent of disease and to plan further treatment.

**Why the Correct Answer is Right**
In this scenario, a complete surgical staging procedure is crucial for accurate staging and planning of postoperative treatment. This involves a unilateral salpingo-oophorectomy (removal of the affected ovary and fallopian tube) along with a hysterectomy (removal of the uterus) and omentectomy (removal of the omentum). The omentum is a common site for metastasis in ovarian cancer, and removing it helps in accurate staging and also helps in reducing the tumor burden. **Option A** is the correct answer because it represents a complete surgical staging procedure.

**Why Each Wrong Option is Incorrect**
**Option B:** Performing a simple ovariectomy (removal of the affected ovary) alone would not be sufficient for staging and would not address the omental metastasis. **Option C:** Hysterectomy alone would not address the omental metastasis and would not be sufficient for staging. **Option D:** Omentectomy alone would not address the ovarian primary tumor and would not be sufficient for staging.

**Clinical Pearl / High-Yield Fact**
In ovarian cancer, a complete surgical staging procedure is essential for accurate staging and planning of postoperative treatment. This procedure involves a unilateral salpingo-oophorectomy, hysterectomy, and omentectomy.

**Correct Answer:** A. Complete staging procedure.