## Core Concept
Familial adenomatous polyposis (FAP) is an autosomal dominant genetic disorder characterized by the development of hundreds to thousands of polyps in the colon and rectum. It is caused by mutations in the **APC** (adenomatous polyposis coli) gene, which is a tumor suppressor gene. If left untreated, there is a nearly 100% risk of developing colorectal cancer.

## Why the Correct Answer is Right
The correct answer relates to the characteristics of FAP. FAP is indeed associated with the development of multiple adenomatous polyps in the colon and rectum, an increased risk of colorectal cancer, and an autosomal dominant pattern of inheritance. Extracolonic manifestations can include osteomas, dental abnormalities, and congenital hypertrophy of the retinal pigment epithelium (CHRPE). The statement that is not true regarding FAP needs to be identified among the options.

## Why Each Wrong Option is Incorrect
Given that the question and specific details about the options (A, B, C, D) are not provided, let's hypothetically analyze:
- **Option A:** If a statement about the autosomal dominant inheritance of FAP is made, it would be correct and not the answer.
- **Option B:** If a statement about the association with colorectal cancer is made, it would also be correct.
- **Option C:** Similarly, if a statement about the presence of multiple polyps is made, it would be accurate.
- **Option D:** This would be incorrect based on the question stem.

For example, if **Option D** stated that FAP is associated with a low risk of colorectal cancer, it would be incorrect because FAP significantly increases the risk of colorectal cancer.

## Clinical Pearl / High-Yield Fact
A key point to remember is that FAP is caused by mutations in the **APC gene** and is characterized by the development of hundreds to thousands of adenomatous polyps. Early diagnosis and treatment, often involving colectomy, are crucial to prevent colorectal cancer.

## Correct Answer Line
**Correct Answer: D.**