**Core Concept**
Crohn's disease is a type of inflammatory bowel disease (IBD) characterized by chronic inflammation of the gastrointestinal tract. It can affect any part of the GI tract, from the mouth to the anus, but most commonly affects the terminal ileum and the beginning of the colon. The disease is characterized by a transmural inflammation, meaning it affects all layers of the intestinal wall.

**Why the Correct Answer is Right**
Crohn's disease is known for its skip lesions, which are areas of inflammation that skip over healthy sections of the intestine. This is in contrast to ulcerative colitis, which typically affects the colon in a continuous pattern. The skip lesions in Crohn's disease are thought to be due to the abnormal immune response and the failure of the immune system to regulate inflammation. This leads to the formation of granulomas, which are characteristic of Crohn's disease.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not a feature of Crohn's disease. Ulcerative colitis is characterized by a continuous pattern of inflammation, not skip lesions.
**Option B:** This option is incorrect because it is a feature of Crohn's disease, but it is not the correct answer. Granulomas are indeed a hallmark of Crohn's disease.
**Option C:** This option is incorrect because it is a feature of Crohn's disease, but it is not the correct answer. Inflammation of the terminal ileum is a common feature of Crohn's disease.
**Option D:** This option is incorrect because it is a feature of Crohn's disease, but it is not the correct answer. Deep ulcers are a feature of Crohn's disease, but they are not the only feature.

**Clinical Pearl / High-Yield Fact**
A key distinguishing feature of Crohn's disease is the presence of skip lesions, which are areas of inflammation that skip over healthy sections of the intestine. This is in contrast to ulcerative colitis, which typically affects the colon in a continuous pattern.

**Correct Answer: D. Ulcerative colitis is characterized by a continuous pattern of inflammation.