## Core Concept
A Krukenberg tumor is a type of metastatic tumor in the ovary, typically originating from a primary site such as the stomach, breast, or colon. It is characterized by mucin-filled signet-ring cells. The tumor usually spreads to the ovaries through direct extension, lymphatic, or hematogenous routes.

## Why the Correct Answer is Right
Krukenberg tumors are known for their mucin-producing signet-ring cells, which are often associated with a primary gastric carcinoma. The correct answer relates to the characteristic features and common primary sites of Krukenberg tumors.

## Why Each Wrong Option is Incorrect
- **Option A:** Typically, Krukenberg tumors do originate from mucin-producing adenocarcinomas, such as gastric carcinoma. So, stating a common origin like the stomach would generally be true for Krukenberg tumors.
- **Option B:** The presence of signet-ring cells is a hallmark of Krukenberg tumors, making this statement true.
- **Option C:** If an option suggests a feature not commonly associated with Krukenberg tumors, such as a specific immunohistochemical marker not typically used for diagnosis, it would be incorrect in the context of defining characteristics.
- **Option D:** Without specific details on the options, a general incorrect statement might involve a common misconception, such as the tumor's origin or histological features.

## Clinical Pearl / High-Yield Fact
A key point to remember is that Krukenberg tumors often present with **bilateral ovarian enlargement** and are associated with a **poor prognosis** if the primary cancer is not identified and treated early. A classic association is with **gastric adenocarcinoma**, particularly the signet-ring cell type.

## Correct Answer: D.