**Core Concept**
Non-resectability criteria in hilar cholangiocarcinoma refer to the factors that make surgical resection of the tumor impossible or not beneficial for the patient. These criteria are crucial in determining the treatment plan for patients with hilar cholangiocarcinoma, a type of cancer that affects the bile ducts.

**Why the Correct Answer is Right**
The non-resectability criteria for hilar cholangiocarcinoma include:

* **Involvement of the main portal vein or its branches**: This is a significant factor in determining non-resectability, as it can lead to liver dysfunction or failure post-surgery.
* **Involvement of the hepatic artery**: Similar to the portal vein, involvement of the hepatic artery can lead to liver dysfunction or failure post-surgery.
* **Involvement of the superior mesenteric vein**: This can also lead to liver dysfunction or failure post-surgery.
* **Distant metastasis**: The presence of distant metastasis, such as to the lungs or liver, makes surgical resection impossible.
* **Local invasion**: Local invasion of the tumor into adjacent structures, such as the stomach or duodenum, can make surgical resection difficult or impossible.

**Why Each Wrong Option is Incorrect**
**Option A:** Not a recognized non-resectability criterion for hilar cholangiocarcinoma.
**Option B:** Not a recognized non-resectability criterion for hilar cholangiocarcinoma.
**Option D:** Not a recognized non-resectability criterion for hilar cholangiocarcinoma.

**Clinical Pearl / High-Yield Fact**
When evaluating hilar cholangiocarcinoma for resectability, it is essential to assess the involvement of major vascular structures, such as the portal vein, hepatic artery, and superior mesenteric vein. This can be done using imaging studies, such as MRI or CT scans.

**Correct Answer:** Not provided