**Core Concept**
Chron's disease is a type of inflammatory bowel disease (IBD) characterized by chronic inflammation of the gastrointestinal tract, primarily affecting the terminal ileum and the beginning of the colon. The pathogenesis of Chron's disease involves a complex interplay between genetic predisposition, environmental factors, and an aberrant immune response.

**Why the Correct Answer is Right**
The earliest change in the intestine in Chron's disease is the loss of goblet cells, which are responsible for producing mucus. This event is followed by an increase in Paneth cells, which secrete antimicrobial peptides. The loss of goblet cells disrupts the intestinal barrier function, leading to increased permeability and the translocation of bacteria across the epithelial layer, triggering an inflammatory response. This sequence of events is crucial in the development of the disease.

**Why Each Wrong Option is Incorrect**
**Option A:** Ulceration is a feature of Chron's disease, but it is not the earliest change. Ulceration occurs as a result of chronic inflammation and tissue damage.
**Option B:** Crypt abscesses are a hallmark of Chron's disease, but they are a consequence of the inflammatory process, not the initial event.
**Option C:** Inflammation is a key feature of Chron's disease, but it is not the earliest change. Inflammation occurs as a result of the loss of goblet cells and the subsequent increase in Paneth cells.

**Clinical Pearl / High-Yield Fact**
Remember that the loss of goblet cells is the earliest change in Chron's disease, and it disrupts the intestinal barrier function, leading to increased permeability and inflammation.

**Correct Answer:** A. Loss of goblet cells.