## Core Concept
The question tests knowledge of screening methods for colon cancer. Colon cancer screening is crucial for early detection and prevention of colorectal cancer. Various methods are available, including imaging and endoscopic techniques.

## Why the Correct Answer is Right
The correct answer, , is a method not typically used or recommended for screening of colon cancer. Common screening methods include colonoscopy, sigmoidoscopy, fecal occult blood test (FOBT), fecal immunochemical test (FIT), and CT colonography.

## Why Each Wrong Option is Incorrect
* **Option A:** - This option is actually a correct method for screening of colon cancer.
* **Option B:** - This option is also a recognized method for screening of colon cancer.
* **Option C:** - Similarly, this is a valid screening method for colon cancer.

## Clinical Pearl / High-Yield Fact
A key point to remember is that while several methods are available for screening, the choice of method often depends on patient risk factors, symptoms, and preferences. For instance, colonoscopy is considered the gold standard for colon cancer screening but may not be suitable for all patients due to its invasive nature.

## Correct Answer: D.