**Core Concept**
The question is testing knowledge of the clinical utility and limitations of the CA 125 tumor marker in the diagnosis and monitoring of ovarian cancer. CA 125 is a glycoprotein antigen that is often elevated in the serum of patients with epithelial ovarian cancer, but it can also be elevated in other conditions.

**Why the Correct Answer is Right**
CA 125 is a non-specific tumor marker that can be elevated in various conditions, including ovarian cancer, endometriosis, pelvic inflammatory disease, and benign ovarian cysts. In the context of ovarian cancer, CA 125 levels can be elevated in up to 80% of cases, but it is not a reliable marker for early detection or screening due to its non-specificity.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided.
* **Option B:** This option is not provided.
* **Option C:** This option is not provided.
* **Option D:** This option is not provided.

**Clinical Pearl / High-Yield Fact**
It's essential to note that CA 125 levels can fluctuate in patients with ovarian cancer, and a single elevated value does not necessarily confirm the diagnosis. A decline in CA 125 levels after treatment is often a good prognostic sign, but a rising level can indicate recurrence.

**Correct Answer:** (Note: The correct option is not provided, as it was not given in the question. Please provide the correct options for a complete explanation.)